vxfs warning fixes

gcc-4.3:

fs/freevxfs/vxfs_lookup.c: In function 'vxfs_find_entry':
fs/freevxfs/vxfs_lookup.c:139: warning: cast from pointer to integer of different size
fs/freevxfs/vxfs_lookup.c: In function 'vxfs_readdir':
fs/freevxfs/vxfs_lookup.c:294: warning: cast from pointer to integer of different size

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>