drm/radeon/kms: avoid possible oops (call gart_fini before gart_disable)

radeon_gart_fini might call GART unbind callback function which
might try to access GART table but if gart_disable is call first
the GART table will be unmapped so any access to it will oops.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/rs400.c b/drivers/gpu/drm/radeon/rs400.c
index 18d6efb..590815c 100644
--- a/drivers/gpu/drm/radeon/rs400.c
+++ b/drivers/gpu/drm/radeon/rs400.c
@@ -203,9 +203,9 @@
 
 void rs400_gart_fini(struct radeon_device *rdev)
 {
+	radeon_gart_fini(rdev);
 	rs400_gart_disable(rdev);
 	radeon_gart_table_ram_free(rdev);
-	radeon_gart_fini(rdev);
 }
 
 int rs400_gart_set_page(struct radeon_device *rdev, int i, uint64_t addr)