drm/xe: Use a NULL pointer instead of 0.

The last argument of xe_pcode_read() is a pointer. Use NULL instead of 0.

Fixes: 92d44a4 ("drm/xe/hwmon: Expose card reactive critical power")
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Francois Dugast <francois.dugast@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240117134048.165425-6-thomas.hellstrom@linux.intel.com

drivers/gpu/drm/xe/xe_hwmon.c

@@ -419,7 +419,7 @@ static int xe_hwmon_pcode_read_i1(struct xe_gt *gt, u32 *uval)
 
 	return xe_pcode_read(gt, PCODE_MBOX(PCODE_POWER_SETUP,
 			     POWER_SETUP_SUBCOMMAND_READ_I1, 0),
-			     uval, 0);
+			     uval, NULL);
 }
 
 static int xe_hwmon_pcode_write_i1(struct xe_gt *gt, u32 uval)