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/file-item.c b/fs/btrfs/file-item.c
index 1c50a7b..763fd17 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -25,6 +25,7 @@
 #include "transaction.h"
 #include "volumes.h"
 #include "print-tree.h"
+#include "compression.h"
 
 #define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
 				   sizeof(struct btrfs_item) * 2) / \