[media] video/cx231xx: Fix sparse warning: Using plain integer as NULL pointer

This patch fixes the warning "Using plain integer as NULL pointer",
generated by sparse, by replacing the offending 0s with NULL.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Reviewed-by: Devin Heitmueller <dheitmueller@hauppauge.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx231xx/cx231xx-417.c

@@ -942,13 +942,13 @@ static int cx231xx_load_firmware(struct cx231xx *dev)
 
 	p_current_fw = vmalloc(1884180 * 4);
 	p_fw = p_current_fw;
-	if (p_current_fw == 0) {
+	if (p_current_fw == NULL) {
 		dprintk(2, "FAIL!!!\n");
 		return -1;
 	}
 
 	p_buffer = vmalloc(4096);
-	if (p_buffer == 0) {
+	if (p_buffer == NULL) {
 		dprintk(2, "FAIL!!!\n");
 		return -1;
 	}

drivers/media/video/cx231xx/cx231xx-cards.c

@@ -360,19 +360,19 @@ struct cx231xx_board cx231xx_boards[] = {
 			.type = CX231XX_VMUX_TELEVISION,
 			.vmux = CX231XX_VIN_3_1,
 			.amux = CX231XX_AMUX_VIDEO,
-			.gpio = 0,
+			.gpio = NULL,
 		}, {
 			.type = CX231XX_VMUX_COMPOSITE1,
 			.vmux = CX231XX_VIN_2_1,
 			.amux = CX231XX_AMUX_LINE_IN,
-			.gpio = 0,
+			.gpio = NULL,
 		}, {
 			.type = CX231XX_VMUX_SVIDEO,
 			.vmux = CX231XX_VIN_1_1 |
 				(CX231XX_VIN_1_2 << 8) |
 				CX25840_SVIDEO_ON,
 			.amux = CX231XX_AMUX_LINE_IN,
-			.gpio = 0,
+			.gpio = NULL,
 		} },
 	},
 	[CX231XX_BOARD_HAUPPAUGE_USBLIVE2] = {
@@ -391,14 +391,14 @@ struct cx231xx_board cx231xx_boards[] = {
 			.type = CX231XX_VMUX_COMPOSITE1,
 			.vmux = CX231XX_VIN_2_1,
 			.amux = CX231XX_AMUX_LINE_IN,
-			.gpio = 0,
+			.gpio = NULL,
 		}, {
 			.type = CX231XX_VMUX_SVIDEO,
 			.vmux = CX231XX_VIN_1_1 |
 				(CX231XX_VIN_1_2 << 8) |
 				CX25840_SVIDEO_ON,
 			.amux = CX231XX_AMUX_LINE_IN,
-			.gpio = 0,
+			.gpio = NULL,
 		} },
 	},
 	[CX231XX_BOARD_PV_PLAYTV_USB_HYBRID] = {
@@ -425,19 +425,19 @@ struct cx231xx_board cx231xx_boards[] = {
 			.type = CX231XX_VMUX_TELEVISION,
 			.vmux = CX231XX_VIN_3_1,
 			.amux = CX231XX_AMUX_VIDEO,
-			.gpio = 0,
+			.gpio = NULL,
 		}, {
 			.type = CX231XX_VMUX_COMPOSITE1,
 			.vmux = CX231XX_VIN_2_1,
 			.amux = CX231XX_AMUX_LINE_IN,
-			.gpio = 0,
+			.gpio = NULL,
 		}, {
 			.type = CX231XX_VMUX_SVIDEO,
 			.vmux = CX231XX_VIN_1_1 |
 				(CX231XX_VIN_1_2 << 8) |
 				CX25840_SVIDEO_ON,
 			.amux = CX231XX_AMUX_LINE_IN,
-			.gpio = 0,
+			.gpio = NULL,
 		} },
 	},
 	[CX231XX_BOARD_PV_XCAPTURE_USB] = {