switch ->setxattr() to passing dentry and inode separately

smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.

Similar change for ->getxattr() had been done in commit ce23e64.  Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.

Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/libfs.c b/fs/libfs.c
index 8765ff1..3db2721 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -1118,8 +1118,9 @@
 	return -EPERM;
 }
 
-static int empty_dir_setxattr(struct dentry *dentry, const char *name,
-			      const void *value, size_t size, int flags)
+static int empty_dir_setxattr(struct dentry *dentry, struct inode *inode,
+			      const char *name, const void *value,
+			      size_t size, int flags)
 {
 	return -EOPNOTSUPP;
 }