ocfs2: Take the inode out of the metadata read/write paths.

We are really passing the inode into the ocfs2_read/write_blocks()
functions to get at the metadata cache.  This commit passes the cache
directly into the metadata block functions, divorcing them from the
inode.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index f2bb1a0..dbd8a16 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -862,8 +862,8 @@
 			BUG_ON(bhs[done + i]->b_blocknr != (p_block + i));
 		}
 
-		rc = ocfs2_read_blocks(inode, p_block, count, bhs + done,
-				       flags, validate);
+		rc = ocfs2_read_blocks(INODE_CACHE(inode), p_block, count,
+				       bhs + done, flags, validate);
 		if (rc) {
 			mlog_errno(rc);
 			break;