fs: btrfs: Fix not all CHUNK_ITEMs being read from CHUNK_TREE

fs: btrfs: Fix not all CHUNK_ITEMs being read from CHUNK_TREE

This causes errors when translating logical addresses to physical:
  btrfs_map_logical_to_physical: Cannot map logical address <addr> to physical
  btrfs_file_read: Error reading extent

The behavior of btrfs_map_logical_to_physical() is to stop traversing
CHUNK_TREE when it encounters first non-CHUNK_ITEM, which makes
only some portion of CHUNK_ITEMs being read.
Change it to skip over non-chunk items.

Signed-off-by: Yevgeny Popovych <yevgenyp@pointgrab.com>
Cc: Marek Behun <marek.behun@nic.cz>
Cc: Sergey Struzh <sergeys@pointgrab.com>
Reviewed-by: Marek Behun <marek.behun@nic.cz>