afs: Fix some checker issues

Remove an unused global variable and make another static as reported by
make C=1.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org

fs/afs/volume.c

@@ -9,8 +9,7 @@
 #include <linux/slab.h>
 #include "internal.h"
 
-unsigned __read_mostly afs_volume_gc_delay = 10;
-unsigned __read_mostly afs_volume_record_life = 60 * 60;
+static unsigned __read_mostly afs_volume_record_life = 60 * 60;
 
 /*
  * Insert a volume into a cell.  If there's an existing volume record, that is