regularize format of source file headers, no code changes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/util-linux/volume_id/btrfs.c b/util-linux/volume_id/btrfs.c
index 338a487..a3ddf97 100644
--- a/util-linux/volume_id/btrfs.c
+++ b/util-linux/volume_id/btrfs.c
@@ -18,14 +18,13 @@
  *	License along with this library; if not, write to the Free Software
  *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
-
-//kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_BTRFS) += btrfs.o
-
 //config:config FEATURE_VOLUMEID_BTRFS
 //config:	bool "btrfs filesystem"
 //config:	default y
 //config:	depends on VOLUMEID
 
+//kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_BTRFS) += btrfs.o
+
 #include "volume_id_internal.h"
 
 #define BTRFS_UUID_SIZE 16