ocfs2: Remove struct ocfs2_journal_handle in favor of handle_t

This is mostly a search and replace as ocfs2_journal_handle is now no more
than a container for a handle_t pointer.

ocfs2_commit_trans() becomes very straight forward, and we remove some out
of date comments / code.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h
index 12ba897..0b82e80 100644
--- a/fs/ocfs2/alloc.h
+++ b/fs/ocfs2/alloc.h
@@ -28,7 +28,7 @@
 
 struct ocfs2_alloc_context;
 int ocfs2_insert_extent(struct ocfs2_super *osb,
-			struct ocfs2_journal_handle *handle,
+			handle_t *handle,
 			struct inode *inode,
 			struct buffer_head *fe_bh,
 			u64 blkno,