cppcheck: fix unchecked realloc in lxc_info.c

src/lxc/lxc_info.c

@@ -50,9 +50,13 @@ static int filter_count = 0;
 
 static int my_parser(struct lxc_arguments* args, int c, char* arg)
 {
+	char **newk;
 	switch (c) {
 	case 'c':
-		key = realloc(key, keys+1 * sizeof(key[0]));
+		newk = realloc(key, keys+1 * sizeof(key[0]));
+		if (!newk)
+			return -1;
+		key = newk;
 		key[keys] = arg;
 		keys++;
 		break;