scsi: fix upper bounds check of sense key in scsi_sense_key_string()

Commit 655ee63c ("scsi constants: command, sense key + additional
sense string") added a "Completed" sense string with key 0xF to
snstext[], but failed to updated the upper bounds check of the sense key
in scsi_sense_key_string().

Fixes: 655ee63c ("[SCSI] scsi constants: command, sense key + additional sense strings")
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/constants.c

@@ -361,8 +361,9 @@ static const char * const snstext[] = {
 
 /* Get sense key string or NULL if not available */
 const char *
-scsi_sense_key_string(unsigned char key) {
-	if (key <= 0xE)
+scsi_sense_key_string(unsigned char key)
+{
+	if (key < ARRAY_SIZE(snstext))
 		return snstext[key];
 	return NULL;
 }