V4L/DVB (9601): ttusb_dec: Add NULL pointer validation

Added validation for NULL pointer

Signed-off-by: Douglas Schilling Landgraf <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/dvb/ttusb-dec/ttusb_dec.c

···
 						ISO_BUF_COUNT),
 					       &dec->iso_dma_handle);
 
+	if (!dec->iso_buffer) {
+		dprintk("%s: pci_alloc_consistent - not enough memory\n",
+			__func__);
+		return -ENOMEM;
+	}
+
 	memset(dec->iso_buffer, 0,
 	       ISO_FRAME_SIZE * (FRAMES_PER_ISO_BUF * ISO_BUF_COUNT));