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>

fs/btrfs/raid56.c

@@ -410,7 +410,7 @@ static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
 /*
  * remove everything in the cache
  */
-void btrfs_clear_rbio_cache(struct btrfs_fs_info *info)
+static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info)
 {
 	struct btrfs_stripe_hash_table *table;
 	unsigned long flags;
@@ -1010,12 +1010,12 @@ static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio)
  * this will try to merge into existing bios if possible, and returns
  * zero if all went well.
  */
-int rbio_add_io_page(struct btrfs_raid_bio *rbio,
-		     struct bio_list *bio_list,
-		     struct page *page,
-		     int stripe_nr,
-		     unsigned long page_index,
-		     unsigned long bio_max_len)
+static int rbio_add_io_page(struct btrfs_raid_bio *rbio,
+			    struct bio_list *bio_list,
+			    struct page *page,
+			    int stripe_nr,
+			    unsigned long page_index,
+			    unsigned long bio_max_len)
 {
 	struct bio *last = bio_list->tail;
 	u64 last_end = 0;