Fix missing-prototype errors in sample programs

Signed-off-by: Michael Schuster <michael@schuster.ms>
diff --git a/programs/ssl/ssl_context_info.c b/programs/ssl/ssl_context_info.c
index ee2cdb7..9577d2b 100644
--- a/programs/ssl/ssl_context_info.c
+++ b/programs/ssl/ssl_context_info.c
@@ -111,12 +111,12 @@
 /*
  * Basic printing functions
  */
-void print_version(void)
+static void print_version(void)
 {
     printf("%s v%d.%d\n", PROG_NAME, VER_MAJOR, VER_MINOR);
 }
 
-void print_usage(void)
+static void print_usage(void)
 {
     print_version();
     printf("\nThis program is used to deserialize an Mbed TLS SSL session from the base64 code provided\n"
@@ -138,7 +138,7 @@
         );
 }
 
-void printf_dbg(const char *str, ...)
+static void printf_dbg(const char *str, ...)
 {
     if (debug) {
         va_list args;
@@ -151,7 +151,7 @@
 }
 
 MBEDTLS_PRINTF_ATTRIBUTE(1, 2)
-void printf_err(const char *str, ...)
+static void printf_err(const char *str, ...)
 {
     va_list args;
     va_start(args, str);
@@ -165,7 +165,7 @@
 /*
  * Exit from the program in case of error
  */
-void error_exit(void)
+static void error_exit(void)
 {
     if (NULL != b64_file) {
         fclose(b64_file);
@@ -176,7 +176,7 @@
 /*
  * This function takes the input arguments of this program
  */
-void parse_arguments(int argc, char *argv[])
+static void parse_arguments(int argc, char *argv[])
 {
     int i = 1;
 
@@ -223,7 +223,7 @@
 /*
  * This function prints base64 code to the stdout
  */
-void print_b64(const uint8_t *b, size_t len)
+static void print_b64(const uint8_t *b, size_t len)
 {
     size_t i = 0;
     const uint8_t *end = b + len;
@@ -247,7 +247,7 @@
  * /p in_line   number of bytes in one line
  * /p prefix    prefix for the new lines
  */
-void print_hex(const uint8_t *b, size_t len,
+static void print_hex(const uint8_t *b, size_t len,
                const size_t in_line, const char *prefix)
 {
     size_t i = 0;
@@ -271,7 +271,7 @@
 /*
  *  Print the value of time_t in format e.g. 2020-01-23 13:05:59
  */
-void print_time(const uint64_t *time)
+static void print_time(const uint64_t *time)
 {
 #if defined(MBEDTLS_HAVE_TIME)
     char buf[20];
@@ -292,7 +292,7 @@
 /*
  * Print the input string if the bit is set in the value
  */
-void print_if_bit(const char *str, int bit, int val)
+static void print_if_bit(const char *str, int bit, int val)
 {
     if (bit & val) {
         printf("\t%s\n", str);
@@ -302,7 +302,7 @@
 /*
  * Return pointer to hardcoded "enabled" or "disabled" depending on the input value
  */
-const char *get_enabled_str(int is_en)
+static const char *get_enabled_str(int is_en)
 {
     return (is_en) ? "enabled" : "disabled";
 }
@@ -310,7 +310,7 @@
 /*
  * Return pointer to hardcoded MFL string value depending on the MFL code at the input
  */
-const char *get_mfl_str(int mfl_code)
+static const char *get_mfl_str(int mfl_code)
 {
     switch (mfl_code) {
         case MBEDTLS_SSL_MAX_FRAG_LEN_NONE:
@@ -343,7 +343,7 @@
  * \retval      number of bytes written in to the b64 buffer or 0 in case no more
  *              data was found
  */
-size_t read_next_b64_code(uint8_t **b64, size_t *max_len)
+static size_t read_next_b64_code(uint8_t **b64, size_t *max_len)
 {
     int valid_balance = 0;  /* balance between valid and invalid characters */
     size_t len = 0;
@@ -443,7 +443,7 @@
  * /p ssl   pointer to serialized certificate
  * /p len   number of bytes in the buffer
  */
-void print_deserialized_ssl_cert(const uint8_t *ssl, uint32_t len)
+static void print_deserialized_ssl_cert(const uint8_t *ssl, uint32_t len)
 {
     enum { STRLEN = 4096 };
     mbedtls_x509_crt crt;
@@ -509,7 +509,7 @@
  * /p len               number of bytes in the buffer
  * /p session_cfg_flag  session configuration flags
  */
-void print_deserialized_ssl_session(const uint8_t *ssl, uint32_t len,
+static void print_deserialized_ssl_session(const uint8_t *ssl, uint32_t len,
                                     int session_cfg_flag)
 {
     const struct mbedtls_ssl_ciphersuite_t *ciphersuite_info;
@@ -746,7 +746,7 @@
  * /p ssl   pointer to serialized session
  * /p len   number of bytes in the buffer
  */
-void print_deserialized_ssl_context(const uint8_t *ssl, size_t len)
+static void print_deserialized_ssl_context(const uint8_t *ssl, size_t len)
 {
     const uint8_t *end = ssl + len;
     uint32_t session_len;