New helper - current_umask()

current->fs->umask is what most of fs_struct users are doing.
Put that into a helper function.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index baac910..9dcc6e7 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -832,7 +832,7 @@
 		 * All right, let's create it.
 		 */
 		mode = S_IFSOCK |
-		       (SOCK_INODE(sock)->i_mode & ~current->fs->umask);
+		       (SOCK_INODE(sock)->i_mode & ~current_umask());
 		err = mnt_want_write(nd.path.mnt);
 		if (err)
 			goto out_mknod_dput;