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

commit a87eeb90 upstream.

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")
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>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/scsi/constants.c

@@ -1335,9 +1335,10 @@ static const char * const snstext[] = {
 
 /* Get sense key string or NULL if not available */
 const char *
-scsi_sense_key_string(unsigned char key) {
+scsi_sense_key_string(unsigned char key)
+{
 #ifdef CONFIG_SCSI_CONSTANTS
-	if (key <= 0xE)
+	if (key < ARRAY_SIZE(snstext))
 		return snstext[key];
 #endif
 	return NULL;