xfs: factor all the kmalloc-or-vmalloc fallback allocations

We have quite a few places now where we do:

	x = kmem_zalloc(large size)
	if (!x)
		x = kmem_zalloc_large(large size)

and do a similar dance when freeing the memory. kmem_free() already
does the correct freeing dance, and kmem_zalloc_large() is only ever
called in these constructs, so just factor it all into
kmem_zalloc_large() and kmem_free().

Signed-off-by: Dave Chinner <dchinner@redhat.com>
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 8a67d53..084b3e1 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -495,7 +495,7 @@
 	/*
 	 * Done, we're either out of filesystem or space to put the data.
 	 */
-	kmem_free_large(irbuf);
+	kmem_free(irbuf);
 	*ubcountp = ubelem;
 	/*
 	 * Found some inodes, return them now and return the error next time.