[PATCH] drm/amd/display: fix ifnullfree.cocci warnings

[Harry Wentland]

On 2017-10-12 07:17 PM, kbuild test robot wrote:
> drivers/gpu/drm/amd/amdgpu/../display/dc/gpio/gpio_service.c:134:3-8: WARNING: NULL check before freeing functions like kfree, debugfs_remove, debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider reorganizing relevant code to avoid passing NULL values.
> drivers/gpu/drm/amd/amdgpu/../display/dc/gpio/gpio_service.c:175:4-9: WARNING: NULL check before freeing functions like kfree, debugfs_remove, debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider reorganizing relevant code to avoid passing NULL values.
> 
>  NULL check before some freeing functions is not needed.
> 
>  Based on checkpatch warning
>  "kfree(NULL) is safe this check is probably not required"
>  and kfreeaddr.cocci by Julia Lawall.
> 
> Generated by: scripts/coccinelle/free/ifnullfree.cocci
> 
> Fixes: f09cd1f46388 ("drm/amd/display: Use kernel alloc/free")
> Signed-off-by: Fengguang Wu <fengguang.wu at intel.com>

Reviewed-by: Harry Wentland <harry.wentland at amd.com>

Harry

> ---
> 
>  gpio_service.c |    6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> --- a/drivers/gpu/drm/amd/amdgpu/../display/dc/gpio/gpio_service.c
> +++ b/drivers/gpu/drm/amd/amdgpu/../display/dc/gpio/gpio_service.c
> @@ -130,8 +130,7 @@ failure_2:
>  
>  		slot = service->busyness[index_of_id];
>  
> -		if (slot)
> -			kfree(slot);
> +		kfree(slot);
>  	};
>  
>  failure_1:
> @@ -171,8 +170,7 @@ void dal_gpio_service_destroy(
>  		do {
>  			uint32_t *slot = (*ptr)->busyness[index_of_id];
>  
> -			if (slot)
> -				kfree(slot);
> +			kfree(slot);
>  
>  			++index_of_id;
>  		} while (index_of_id < GPIO_ID_COUNT);
>