Fix a portability issue

This should fix the following compilation issue:

```
/wrkdirs/usr/ports/security/snuffleupagus/work-php83/snuffleupagus-0.10.0/src/sp_utils.c:438:37: error: too few arguments provided to function-like macro invocation
  438 |     memcpy(mb_name, ZEND_STRL("mb_"));
      |                                     ^
/usr/include/ssp/string.h:117:9: note: macro 'memcpy' defined here
  117 | #define memcpy(dst, src, len) __ssp_bos_check3(memcpy, dst, src, len)
```

src/sp_utils.c

@@ -435,8 +435,8 @@ bool hook_function(const char* original_name, HashTable* hook_table, zif_handler
     if (NULL == mb_name) {
       return FAILURE;
     }
-    memcpy(mb_name, ZEND_STRL("mb_"));
-    memcpy(mb_name + 3, VAR_AND_LEN(original_name));
+    memcpy(mb_name, "mb_", 3);
+    memcpy(mb_name + 3, original_name, strlen(original_name));
     _hook_function(mb_name, hook_table, new_function);
     efree(mb_name);
     // LCOV_EXCL_STOP