[nrf noup] zephyr: Fix failure processing of no-response commands

fixup! [nrf noup] zephyr: Add support for WPA CLI zephyr

For commands without any response, the failures are ignored.

Fixes SHEL-2740.

Signed-off-by: Chaitanya Tata <Chaitanya.Tata@nordicsemi.no>

wpa_supplicant/wpa_cli_zephyr.c

@@ -72,15 +72,19 @@ static int _wpa_ctrl_command(struct wpa_ctrl *ctrl, const char *cmd, int print,
 		/* Remove the LF */
 		os_memcpy(resp, buf, len - 1);
 		resp[len - 1] = '\0';
-		if (strncmp(resp, "FAIL", 4) == 0)
-			return -3;
 	}
 
 	if (print) {
 			buf[len] = '\0';
 			if (buf[0] != '\0')
 				printf("%s", buf);
 	}
+
+	if (len > 1 && (strncmp(resp, "FAIL", 4) == 0)) {
+		wpa_printf(MSG_ERROR, "Command failed: %s", resp);
+		return -3;
+	}
+
 	return 0;
 }