power: supply: bq27xxx: fix NULL vs 0 warnings

The driver has a lot of sparse warnings for using 0 as a NULL
pointer when NULL would be appropriate. Change the 0 values
to NULL to fix the warnings, some of which are shown here:

drivers/power/supply/bq27xxx_battery.c:984:23: warning: Using plain integer as NULL pointer
drivers/power/supply/bq27xxx_battery.c:985:23: warning: Using plain integer as NULL pointer
drivers/power/supply/bq27xxx_battery.c:986:23: warning: Using plain integer as NULL pointer
drivers/power/supply/bq27xxx_battery.c:987:23: warning: Using plain integer as NULL pointer
drivers/power/supply/bq27xxx_battery.c:988:23: warning: Using plain integer as NULL pointer
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/bq27xxx_battery.c

@@ -868,11 +868,11 @@ enum bq27xxx_dm_reg_id {
 	BQ27XXX_DM_TERMINATE_VOLTAGE,
 };
 
-#define bq27000_dm_regs 0
-#define bq27010_dm_regs 0
-#define bq2750x_dm_regs 0
-#define bq2751x_dm_regs 0
-#define bq2752x_dm_regs 0
+#define bq27000_dm_regs NULL
+#define bq27010_dm_regs NULL
+#define bq2750x_dm_regs NULL
+#define bq2751x_dm_regs NULL
+#define bq2752x_dm_regs NULL
 
 #if 0 /* not yet tested */
 static struct bq27xxx_dm_reg bq27500_dm_regs[] = {
@@ -881,24 +881,24 @@ static struct bq27xxx_dm_reg bq27500_dm_regs[] = {
 	[BQ27XXX_DM_TERMINATE_VOLTAGE] = { 80, 48, 2, 1000, 32767 },
 };
 #else
-#define bq27500_dm_regs 0
+#define bq27500_dm_regs NULL
 #endif
 
 /* todo create data memory definitions from datasheets and test on chips */
-#define bq27510g1_dm_regs 0
-#define bq27510g2_dm_regs 0
-#define bq27510g3_dm_regs 0
-#define bq27520g1_dm_regs 0
-#define bq27520g2_dm_regs 0
-#define bq27520g3_dm_regs 0
-#define bq27520g4_dm_regs 0
-#define bq27521_dm_regs 0
-#define bq27530_dm_regs 0
-#define bq27531_dm_regs 0
-#define bq27541_dm_regs 0
-#define bq27542_dm_regs 0
-#define bq27546_dm_regs 0
-#define bq27742_dm_regs 0
+#define bq27510g1_dm_regs NULL
+#define bq27510g2_dm_regs NULL
+#define bq27510g3_dm_regs NULL
+#define bq27520g1_dm_regs NULL
+#define bq27520g2_dm_regs NULL
+#define bq27520g3_dm_regs NULL
+#define bq27520g4_dm_regs NULL
+#define bq27521_dm_regs NULL
+#define bq27530_dm_regs NULL
+#define bq27531_dm_regs NULL
+#define bq27541_dm_regs NULL
+#define bq27542_dm_regs NULL
+#define bq27546_dm_regs NULL
+#define bq27742_dm_regs NULL
 
 #if 0 /* not yet tested */
 static struct bq27xxx_dm_reg bq27545_dm_regs[] = {
@@ -907,7 +907,7 @@ static struct bq27xxx_dm_reg bq27545_dm_regs[] = {
 	[BQ27XXX_DM_TERMINATE_VOLTAGE] = { 80, 67, 2, 2800,  3700 },
 };
 #else
-#define bq27545_dm_regs 0
+#define bq27545_dm_regs NULL
 #endif
 
 static struct bq27xxx_dm_reg bq27411_dm_regs[] = {
@@ -937,7 +937,7 @@ static struct bq27xxx_dm_reg bq27426_dm_regs[] = {
 #if 0 /* not yet tested */
 #define bq27441_dm_regs bq27421_dm_regs
 #else
-#define bq27441_dm_regs 0
+#define bq27441_dm_regs NULL
 #endif
 
 #if 0 /* not yet tested */
@@ -947,13 +947,13 @@ static struct bq27xxx_dm_reg bq27621_dm_regs[] = {
 	[BQ27XXX_DM_TERMINATE_VOLTAGE] = { 82, 9, 2, 2500,  3700 },
 };
 #else
-#define bq27621_dm_regs 0
+#define bq27621_dm_regs NULL
 #endif
 
-#define bq27z561_dm_regs 0
-#define bq28z610_dm_regs 0
-#define bq34z100_dm_regs 0
-#define bq78z100_dm_regs 0
+#define bq27z561_dm_regs NULL
+#define bq28z610_dm_regs NULL
+#define bq34z100_dm_regs NULL
+#define bq78z100_dm_regs NULL
 
 #define BQ27XXX_O_ZERO		BIT(0)
 #define BQ27XXX_O_OTDC		BIT(1) /* has OTC/OTD overtemperature flags */