tests: Add mbedtls_test_ prefix to hexcmp()

Add mbedtls_test_ prefix to hexcmp() test helper
function.

Command to change *.function files:
find . -name "*.function" -exec awk -i inplace \
    '{sub(/hexcmp\>/,"mbedtls_test_&")}1' {} \;

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/tests/suites/test_suite_arc4.function b/tests/suites/test_suite_arc4.function
index ae3b032..7f85df6 100644
--- a/tests/suites/test_suite_arc4.function
+++ b/tests/suites/test_suite_arc4.function
@@ -21,7 +21,7 @@
     mbedtls_arc4_setup(&ctx, key_str->x, key_str->len);
     TEST_ASSERT( mbedtls_arc4_crypt(&ctx, src_str->len, src_str->x, dst_str ) == 0 );
 
-    TEST_ASSERT( hexcmp( dst_str, hex_dst_string->x, src_str->len, hex_dst_string->len ) == 0 );
+    TEST_ASSERT( mbedtls_test_hexcmp( dst_str, hex_dst_string->x, src_str->len, hex_dst_string->len ) == 0 );
 
 exit:
     mbedtls_arc4_free( &ctx );