Btrfs: Fix PAGE_CACHE_SHIFT shifts on 32 bit machines

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --cc fs/btrfs/disk-io.c
Simple merge

diff --cc fs/btrfs/extent_map.c
Simple merge

diff --cc fs/btrfs/file.c
Simple merge

diff --cc fs/btrfs/inode.c
Simple merge

diff --cc fs/btrfs/transaction.c
Simple merge