Fix debug mode in example-tls-client

Fixes #242
diff --git a/yotta/data/example-tls-client/main.cpp b/yotta/data/example-tls-client/main.cpp
index 926b483..f97187e 100644
--- a/yotta/data/example-tls-client/main.cpp
+++ b/yotta/data/example-tls-client/main.cpp
@@ -256,19 +256,27 @@
      * Debug callback for mbed TLS
      * Just prints on the USB serial port
      */
-    static void my_debug(void *ctx, int level, const char *str)
+    static void my_debug(void *ctx, int level, const char *file, int line,
+                         const char *str)
     {
+        const char *p, *basename;
         (void) ctx;
-        (void) level;
 
-        printf("%s", str);
+        /* Extract basename from file */
+        for(p = basename = file; *p != '\0'; p++) {
+            if(*p == '/' || *p == '\\') {
+                basename = p + 1;
+            }
+        }
+
+        printf("%s:%04d: |%d| %s", basename, line, level, str);
     }
 
     /**
      * Certificate verification callback for mbed TLS
      * Here we only use it to display information on each cert in the chain
      */
-    static int my_verify(void *data, mbedtls_x509_crt *crt, int depth, int *flags)
+    static int my_verify(void *data, mbedtls_x509_crt *crt, int depth, uint32_t *flags)
     {
         char buf[1024];
         (void) data;