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/fs/ext2/acl.c b/fs/ext2/acl.c
index ae8c4f8..d46e38c 100644
--- a/fs/ext2/acl.c
+++ b/fs/ext2/acl.c
@@ -318,7 +318,7 @@
 				return PTR_ERR(acl);
 		}
 		if (!acl)
-			inode->i_mode &= ~current->fs->umask;
+			inode->i_mode &= ~current_umask();
 	}
 	if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
                struct posix_acl *clone;