The new helper returns index of the mathing string in an array.  We
would use it here.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
        unsigned num_groups;
        int ret;
        const char *group;
-       int i;
 
        if (!pmxops) {
                dev_err(pctldev->dev, "does not support mux function\n");
                return -EINVAL;
        }
        if (map->data.mux.group) {
-               bool found = false;
                group = map->data.mux.group;
-               for (i = 0; i < num_groups; i++) {
-                       if (!strcmp(group, groups[i])) {
-                               found = true;
-                               break;
-                       }
-               }
-               if (!found) {
+               ret = match_string(groups, num_groups, group);
+               if (ret < 0) {
                        dev_err(pctldev->dev,
                                "invalid group \"%s\" for function \"%s\"\n",
                                group, map->data.mux.function);
-                       return -EINVAL;
+                       return ret;
                }
        } else {
                group = groups[0];