staging: speakup: (coding style) Rewrite comparisons to NULL

Rewrite comparisons to NULL so they dont show any checkpatch errors anymore.
"vc_cons[i].d != NULL" => "vc_cons[i].d"

Signed-off-by: Christian Colic <colic.christian@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/speakup/buffers.c

@@ -27,7 +27,7 @@ void speakup_start_ttys(void)
 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
 		if (speakup_console[i] && speakup_console[i]->tty_stopped)
 			continue;
-		if ((vc_cons[i].d != NULL) && (vc_cons[i].d->port.tty != NULL))
+		if ((vc_cons[i].d) && (vc_cons[i].d->port.tty))
 			start_tty(vc_cons[i].d->port.tty);
 	}
 }
@@ -38,7 +38,7 @@ static void speakup_stop_ttys(void)
 	int i;
 
 	for (i = 0; i < MAX_NR_CONSOLES; i++)
-		if ((vc_cons[i].d != NULL) && (vc_cons[i].d->port.tty != NULL))
+		if ((vc_cons[i].d && (vc_cons[i].d->port.tty)))
 			stop_tty(vc_cons[i].d->port.tty);
 }