wifi-scripts: fix failing mesh setup with missing wpa_supplicant

The initialization of mesh interfaces currently fail when wpa_supplicant
is not installed. This is due to the script calling the wpa_supplicant
feature indicator without verifying wpa_supplicant is installed at all.

To avoid failing, first check if wpa_supplicant is installed before
determining the available featureset.

Signed-off-by: David Bauer <[email protected]>

package/network/config/wifi-scripts/files/lib/netifd/wireless/mac80211.sh

@@ -1023,7 +1023,7 @@ mac80211_setup_vif() {
 			json_get_vars $MP_CONFIG_INT $MP_CONFIG_BOOL $MP_CONFIG_STRING
 			wireless_vif_parse_encryption
 			[ -z "$htmode" ] && htmode="NOHT";
-			if wpa_supplicant -vmesh; then
+			if [ -x /usr/sbin/wpa_supplicant ] && wpa_supplicant -vmesh; then
 				mac80211_setup_supplicant || failed=1
 			else
 				mac80211_setup_mesh