drm/radeon: fix typo in function header comment

Signed-off-by: Dmitrii Cherkasov <DCherkasov@luxsoft.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_gart.c

@@ -950,7 +950,7 @@ int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm)
 }
 
 /**
- * radeon_vm_init - tear down a vm instance
+ * radeon_vm_fini - tear down a vm instance
  *
  * @rdev: radeon_device pointer
  * @vm: requested vm