ANDROID: sdcardfs: Propagate dentry down to inode_change_ok()

Since commit 31051c85b5e2 ("fs: Give dentry to inode_change_ok()
instead of inode"), to avoid clearing of capabilities or security
related extended attributes too early, inode_change_ok() will
need to take dentry instead of inode. Propagate it down to
sdcardfs_setattr() and also rename it to setattr_prepare(),
otherwise we run into following build error:

  CC [M]  fs/sdcardfs/inode.o
fs/sdcardfs/inode.c: In function ‘sdcardfs_setattr’:
fs/sdcardfs/inode.c:644:8: error: implicit declaration of function ‘inode_change_ok’ [-Werror=implicit-function-declaration]
  err = inode_change_ok(inode, ia);
        ^

Change-Id: I714b4f4f68b7fea1ac82a71d2f323c76b11fa008
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
diff --git a/fs/sdcardfs/inode.c b/fs/sdcardfs/inode.c
index 17af0c1..947918c 100644
--- a/fs/sdcardfs/inode.c
+++ b/fs/sdcardfs/inode.c
@@ -703,6 +703,7 @@
 	struct iattr lower_ia;
 	struct dentry *parent;
 	struct inode tmp;
+	struct dentry tmp_d;
 	struct inode *top;
 	const struct cred *saved_cred = NULL;
 
@@ -733,13 +734,14 @@
 	tmp.i_size = i_size_read(inode);
 	release_top(SDCARDFS_I(inode));
 	tmp.i_sb = inode->i_sb;
+	tmp_d.d_inode = &tmp;
 
 	/*
-	 * Check if user has permission to change inode.  We don't check if
+	 * Check if user has permission to change dentry.  We don't check if
 	 * this user can change the lower inode: that should happen when
 	 * calling notify_change on the lower inode.
 	 */
-	err = inode_change_ok(&tmp, ia);
+	err = setattr_prepare(&tmp_d, ia);
 
 	if (!err) {
 		/* check the Android group ID */