wiphy: Reduce static allocation size

iwd_device_get_path() is not going to produce longer string than 12
bytes (/ + maximum of uint32_t expressed as a string + '\0').

src/wiphy.c

@@ -319,7 +319,7 @@ static void network_free(void *data)
 
 const char *iwd_device_get_path(struct netdev *netdev)
 {
-	static char path[256];
+	static char path[12];
 
 	snprintf(path, sizeof(path), "/%u", netdev->index);
 	return path;