staging: dgnc: fix checkpatch.pl usage of volatile.

This is a patch to the dgnc_cls.c file that fixes up volatile usage
warning found by the checkpatch.pl tool

Signed-off-by: S. Stalin Srinivasan <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/dgnc/dgnc_cls.c

···
 
 static void cls_parse_modem(struct channel_t *ch, uchar signals)
 {
-	volatile uchar msignals = signals;
+	uchar msignals = signals;
+	ulong lock_flags;
 
 	if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
 		return;
···
 	 * Do altpin switching. Altpin switches DCD and DSR.
 	 * This prolly breaks DSRPACE, so we should be more clever here.
 	 */
+	DGNC_LOCK(ch->ch_lock, lock_flags);
 	if (ch->ch_digi.digi_flags & DIGI_ALTPIN) {
 		uchar mswap = signals;
 		if (mswap & UART_MSR_DDCD) {
···
 			msignals |= UART_MSR_DCD;
 		}
 	}
+	DGNC_UNLOCK(ch->ch_lock, lock_flags);
 
 	/*
 	 * Scrub off lower bits. They signify delta's, which I don't
···
 	 */
 	signals &= 0xf0;
 
+	DGNC_LOCK(ch->ch_lock, lock_flags);
 	if (msignals & UART_MSR_DCD)
 		ch->ch_mistat |= UART_MSR_DCD;
 	else
···
 		ch->ch_mistat |= UART_MSR_CTS;
 	else
 		ch->ch_mistat &= ~UART_MSR_CTS;
+	DGNC_UNLOCK(ch->ch_lock, lock_flags);
 
 
 	DPR_MSIGS((