btrfs: move btrfs_compression_type to compression.h

So that its better organized.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 9d2e8ec..eafdb96 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -26,6 +26,7 @@
 #include "print-tree.h"
 #include "backref.h"
 #include "hash.h"
+#include "compression.h"
 
 /* magic values for the inode_only field in btrfs_log_inode:
  *