scsi_debug: make dump_sector static

fixes warning:
warning: no previous prototype for ‘dump_sector’

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index e2c509e..3a70683 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -2681,7 +2681,7 @@
 	return 0;
 }
 
-void dump_sector(unsigned char *buf, int len)
+static void dump_sector(unsigned char *buf, int len)
 {
 	int i, j, n;