drm/etnaviv: Delete unnecessary checks before two function calls

The functions drm_gem_object_unreference_unlocked() and vunmap() perform
also input parameter validation.
Thus the tests around their calls are not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
[seanpaul tweaked subject]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/9638cd74-ffc5-d9ee-a40c-9b60e860ad8b@users.sourceforge.net

drivers/gpu/drm/etnaviv/etnaviv_gem.c

@@ -535,7 +535,6 @@ void etnaviv_gem_describe_objects(struct etnaviv_drm_private *priv,
 
 static void etnaviv_gem_shmem_release(struct etnaviv_gem_object *etnaviv_obj)
 {
-	if (etnaviv_obj->vaddr)
 	vunmap(etnaviv_obj->vaddr);
 	put_pages(etnaviv_obj);
 }
@@ -670,9 +669,7 @@ static struct drm_gem_object *__etnaviv_gem_new(struct drm_device *dev,
 	return obj;
 
 fail:
-	if (obj)
 	drm_gem_object_unreference_unlocked(obj);
-
 	return ERR_PTR(ret);
 }