module-protocol-native: Fix socket activation

Fix path comparison in is_socket_unix() and don't unset LISTEN_FDS since
the function that uses it is called more than once and it was not unset
when sd_listen_fds() was used.

Fixes #5140

src/modules/module-protocol-pulse/server.c

@@ -576,7 +576,7 @@ static bool is_stale_socket(int fd, const struct sockaddr_un *addr_un)
 
 static int check_socket_activation(const char *path)
 {
-	const int n = listen_fd();
+	const int n = listen_fds();
 
 	for (int i = 0; i < n; i++) {
 		const int fd = LISTEN_FDS_START + i;