btrfs: uapi/linux/btrfs.h migration, move BTRFS_LABEL_SIZE

BTRFS_LABEL_SIZE is required to define the BTRFS_IOC_GET_FSLABEL and
BTRFS_IOC_SET_FSLABEL ioctls.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/ctree.h

@@ -410,7 +410,6 @@ struct btrfs_header {
  * room to translate 14 chunks with 3 stripes each.
  */
 #define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
-#define BTRFS_LABEL_SIZE 256
 
 /*
  * just in case we somehow lose the roots and are not able to mount,

include/uapi/linux/btrfs.h

@@ -23,6 +23,7 @@
 
 #define BTRFS_IOCTL_MAGIC 0x94
 #define BTRFS_VOL_NAME_MAX 255
+#define BTRFS_LABEL_SIZE 256
 
 /* this should be 4k */
 #define BTRFS_PATH_NAME_MAX 4087