iget: stop EXT3 from using iget() and read_inode()

Stop the EXT3 filesystem from using iget() and read_inode().  Replace
ext3_read_inode() with ext3_iget(), and call that instead of iget().
ext3_iget() then uses iget_locked() directly and returns a proper error code
instead of an inode in the event of an error.

ext3_fill_super() returns any error incurred when getting the root inode
instead of EINVAL.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.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/include/linux/ext3_fs.h b/include/linux/ext3_fs.h
index 241c01c..36c5403 100644
--- a/include/linux/ext3_fs.h
+++ b/include/linux/ext3_fs.h
@@ -823,7 +823,7 @@
 	sector_t iblock, unsigned long maxblocks, struct buffer_head *bh_result,
 	int create, int extend_disksize);
 
-extern void ext3_read_inode (struct inode *);
+extern struct inode *ext3_iget(struct super_block *, unsigned long);
 extern int  ext3_write_inode (struct inode *, int);
 extern int  ext3_setattr (struct dentry *, struct iattr *);
 extern void ext3_delete_inode (struct inode *);