btrfs: make static code static & remove dead code

Big patch, but all it does is add statics to functions which
are in fact static, then remove the associated dead-code fallout.

removed functions:

btrfs_iref_to_path()
__btrfs_lookup_delayed_deletion_item()
__btrfs_search_delayed_insertion_item()
__btrfs_search_delayed_deletion_item()
find_eb_for_page()
btrfs_find_block_group()
range_straddles_pages()
extent_range_uptodate()
btrfs_file_extent_length()
btrfs_scrub_cancel_devid()
btrfs_start_transaction_lflush()

btrfs_print_tree() is left because it is used for debugging.
btrfs_start_transaction_lflush() and btrfs_reada_detach() are
left for symmetry.

ulist.c functions are left, another patch will take care of those.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

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

diff --cc fs/btrfs/backref.h
Simple merge

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

diff --cc fs/btrfs/compression.h
Simple merge

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

diff --cc fs/btrfs/ctree.h
Simple merge

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

diff --cc fs/btrfs/dir-item.c
Simple merge

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

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

diff --cc fs/btrfs/extent-tree.c
Simple merge

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

diff --cc fs/btrfs/extent_io.h
Simple merge

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

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

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

diff --cc fs/btrfs/free-space-cache.c
Simple merge

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

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

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

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

diff --cc fs/btrfs/print-tree.h
Simple merge

diff --cc fs/btrfs/raid56.c
Simple merge

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

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

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

diff --cc fs/btrfs/send.h
Simple merge

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

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

diff --cc fs/btrfs/tree-log.c
Simple merge

diff --cc fs/btrfs/tree-log.h
Simple merge

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

diff --cc fs/btrfs/volumes.h
Simple merge

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