drm/ttm: Remove explicit typecasts of vm_private_data

The explicit typcasts are meaningless, so remove them.
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/ttm/ttm_bo_vm.c

@@ -109,8 +109,7 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
 static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
-	struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
-	    vma->vm_private_data;
+	struct ttm_buffer_object *bo = vma->vm_private_data;
 	struct ttm_bo_device *bdev = bo->bdev;
 	unsigned long page_offset;
 	unsigned long page_last;
@@ -300,8 +299,7 @@ static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
 
 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 {
-	struct ttm_buffer_object *bo =
-	    (struct ttm_buffer_object *)vma->vm_private_data;
+	struct ttm_buffer_object *bo = vma->vm_private_data;
 
 	WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
 
@@ -310,7 +308,7 @@ static void ttm_bo_vm_open(struct vm_area_struct *vma)
 
 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 {
-	struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
+	struct ttm_buffer_object *bo = vma->vm_private_data;
 
 	ttm_bo_put(bo);
 	vma->vm_private_data = NULL;