[NET]: sockfd_lookup_light() returns random error for -EBADFD

This applies to 2.6.17-rc2.

There is a missing initialization of err in sockfd_lookup_light() that
could return random error for an invalid file handle.

Signed-off-by: Hua Zhong <hzhong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/socket.c b/net/socket.c
index 23898f4..0ce12df 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -490,6 +490,7 @@
 	struct file *file;
 	struct socket *sock;
 
+	*err = -EBADF;
 	file = fget_light(fd, fput_needed);
 	if (file) {
 		sock = sock_from_file(file, err);