xfs: merge xfs_itobp into xfs_imap_to_bp

All callers of xfs_imap_to_bp want the dinode pointer, so let's calculate it
inside xfs_imap_to_bp.  Once that is done xfs_itobp becomes a fairly pointless
wrapper which can be replaced with direct calls to xfs_imap_to_bp.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index eff577a..01d10a6 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -555,7 +555,7 @@
 
 	/*
 	 * note that requesting valid inode numbers which are not allocated
-	 * to inodes will most likely cause xfs_itobp to generate warning
+	 * to inodes will most likely cause xfs_imap_to_bp to generate warning
 	 * messages about bad magic numbers. This is ok. The fact that
 	 * the inode isn't actually an inode is handled by the
 	 * error check below. Done this way to make the usual case faster