On ppc64, s64 is `long'.

In file included from fs/jfs/jfs_xtree.h:25,
                 from fs/jfs/jfs_incore.h:26,
                 from fs/jfs/super.c:29:
fs/jfs/jfs_btree.h: In function `BT_STACK_DUMP':
fs/jfs/jfs_btree.h:151: warning: long long unsigned int format, s64 arg (arg 2)

Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>