wrappers: Fix the comparison against max_args in clang-target-wrapper

Since we allocate max_args+1 elements, with one extra for the
null terminator, it's ok if we've used up to max_args elements
already.

wrappers/clang-target-wrapper.c

@@ -113,7 +113,7 @@ int _tmain(int argc, TCHAR* argv[]) {
     }
 
     exec_argv[arg] = NULL;
-    if (arg >= max_arg) {
+    if (arg > max_arg) {
         fprintf(stderr, "Too many options added\n");
         abort();
     }