iget: stop JFFS2 from using iget() and read_inode()

Stop the JFFS2 filesystem from using iget() and read_inode().  Replace
jffs2_read_inode() with jffs2_iget(), and call that instead of iget().
jffs2_iget() then uses iget_locked() directly and returns a proper error code
instead of an inode in the event of an error.

jffs2_do_fill_super() returns any error incurred when getting the root inode
instead of EINVAL.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h
index bf64686..1b10d25 100644
--- a/fs/jffs2/os-linux.h
+++ b/fs/jffs2/os-linux.h
@@ -175,7 +175,7 @@
 /* fs.c */
 int jffs2_setattr (struct dentry *, struct iattr *);
 int jffs2_do_setattr (struct inode *, struct iattr *);
-void jffs2_read_inode (struct inode *);
+struct inode *jffs2_iget(struct super_block *, unsigned long);
 void jffs2_clear_inode (struct inode *);
 void jffs2_dirty_inode(struct inode *inode);
 struct inode *jffs2_new_inode (struct inode *dir_i, int mode,