[AF_UNIX]: Use spinlock for unix_table_lock

This lock is actually taken mostly as a writer,
so using a rwlock actually just makes performance
worse especially on chips like the Intel P4.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index b5d785a..3f302ae 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -13,7 +13,7 @@
 #define UNIX_HASH_SIZE	256
 
 extern struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
-extern rwlock_t unix_table_lock;
+extern spinlock_t unix_table_lock;
 
 extern atomic_t unix_tot_inflight;