scsi: replace custom approach to hexdump small buffers

In kernel we have defined specifier (%*ph[C]) to dump small buffers in a
hex format. Replace custom approach by a generic one.

Cc: Jon Mason <jonmason@broadcom.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/sd.c

@@ -2419,9 +2419,7 @@ sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
 		if (sdkp->first_scan || old_wp != sdkp->write_prot) {
 			sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
 				  sdkp->write_prot ? "on" : "off");
-			sd_printk(KERN_DEBUG, sdkp,
-				  "Mode Sense: %02x %02x %02x %02x\n",
-				  buffer[0], buffer[1], buffer[2], buffer[3]);
+			sd_printk(KERN_DEBUG, sdkp, "Mode Sense: %4ph\n", buffer);
 		}
 	}
 }