V4L/DVB (13687): cx231xx: use NULL when pointer is needed

The gpio field in the cx231xx_board.input structure is a pointer. Eliminate the
following sparse warnings (see "make C=1"):
 * cx231xx-cards.c:72:13: warning: Using plain integer as NULL pointer
 * cx231xx-cards.c:77:13: warning: Using plain integer as NULL pointer
 * cx231xx-cards.c:84:13: warning: Using plain integer as NULL pointer
 * cx231xx-cards.c:111:13: warning: Using plain integer as NULL pointer
 * cx231xx-cards.c:116:13: warning: Using plain integer as NULL pointer
 * cx231xx-cards.c:123:13: warning: Using plain integer as NULL pointer
 * cx231xx-cards.c:151:13: warning: Using plain integer as NULL pointer
 * cx231xx-cards.c:156:13: warning: Using plain integer as NULL pointer
 * cx231xx-cards.c:163:13: warning: Using plain integer as NULL pointer

Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

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

@@ -68,19 +68,19 @@ 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,
 			}
 		},
 	},
@@ -107,19 +107,19 @@ 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,
 			}
 		},
 	},
@@ -147,19 +147,19 @@ 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,
 			}
 		},
 	},