Don't define MBEDTLS-namespace macros in sha256.c
diff --git a/library/sha256.c b/library/sha256.c
index 8df4fb1..9967d52 100644
--- a/library/sha256.c
+++ b/library/sha256.c
@@ -74,13 +74,13 @@
 } while( 0 )
 #endif
 
-#define MBEDTLS_SHA256_VALIDATE_RET(cond)                           \
+#define SHA256_VALIDATE_RET(cond)                           \
     MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_SHA256_BAD_INPUT_DATA )
-#define MBEDTLS_SHA256_VALIDATE(cond)  MBEDTLS_INTERNAL_VALIDATE( cond )
+#define SHA256_VALIDATE(cond)  MBEDTLS_INTERNAL_VALIDATE( cond )
 
 void mbedtls_sha256_init( mbedtls_sha256_context *ctx )
 {
-    MBEDTLS_SHA256_VALIDATE( ctx != NULL );
+    SHA256_VALIDATE( ctx != NULL );
 
     memset( ctx, 0, sizeof( mbedtls_sha256_context ) );
 }
@@ -96,8 +96,8 @@
 void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
                            const mbedtls_sha256_context *src )
 {
-    MBEDTLS_SHA256_VALIDATE( dst != NULL );
-    MBEDTLS_SHA256_VALIDATE( src != NULL );
+    SHA256_VALIDATE( dst != NULL );
+    SHA256_VALIDATE( src != NULL );
 
     *dst = *src;
 }
@@ -107,8 +107,8 @@
  */
 int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 )
 {
-    MBEDTLS_SHA256_VALIDATE_RET( ctx != NULL );
-    MBEDTLS_SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
 
     ctx->total[0] = 0;
     ctx->total[1] = 0;
@@ -204,8 +204,8 @@
     uint32_t A[8];
     unsigned int i;
 
-    MBEDTLS_SHA256_VALIDATE_RET( ctx != NULL );
-    MBEDTLS_SHA256_VALIDATE_RET( (const unsigned char *)data != NULL );
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( (const unsigned char *)data != NULL );
 
     for( i = 0; i < 8; i++ )
         A[i] = ctx->state[i];
@@ -278,8 +278,8 @@
     size_t fill;
     uint32_t left;
 
-    MBEDTLS_SHA256_VALIDATE_RET( ctx != NULL );
-    MBEDTLS_SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
 
     if( ilen == 0 )
         return( 0 );
@@ -339,8 +339,8 @@
     uint32_t used;
     uint32_t high, low;
 
-    MBEDTLS_SHA256_VALIDATE_RET( ctx != NULL );
-    MBEDTLS_SHA256_VALIDATE_RET( (unsigned char *)output != NULL );
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( (unsigned char *)output != NULL );
 
     /*
      * Add padding: 0x80 then 0x00 until 8 bytes remain for the length
@@ -416,9 +416,9 @@
     int ret;
     mbedtls_sha256_context ctx;
 
-    MBEDTLS_SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
-    MBEDTLS_SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
-    MBEDTLS_SHA256_VALIDATE_RET( (unsigned char *)output != NULL );
+    SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
+    SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
+    SHA256_VALIDATE_RET( (unsigned char *)output != NULL );
 
     mbedtls_sha256_init( &ctx );