Rename prefixed mysqlnd functions - prefixed with undescore, which were

accessible through a macro. Also removing the access macros.
These prefixed functions were used, similarly to many functions in Zend2,
because of TSRMLS - the macro was adding the the tsrm pointer to the call.
However, as in Zend3 no TSRM pointers are passed down the stack, because of
the usage of cached TSRM pointer in a real thread local variable, these
macros and prefixed naming have lost their purpose.

ext/mysqlnd/mysqlnd_debug.c

@@ -723,8 +723,8 @@ mysqlnd_debug_init(const char * skip_functions[])
 /* }}} */
 
 
-/* {{{ _mysqlnd_debug */
-PHPAPI void _mysqlnd_debug(const char * mode)
+/* {{{ mysqlnd_debug */
+PHPAPI void mysqlnd_debug(const char * mode)
 {
 #if PHP_DEBUG
 	MYSQLND_DEBUG * dbg = MYSQLND_G(dbg);