drm/ast: switch to drm_*_get(), drm_*_put() helpers

Use drm_*_get() and drm_*_put() helpers instead of drm_*_reference()
and drm_*_unreference() helpers.

drm_*_reference() and drm_*_unreference() functions are just
compatibility alias for drm_*_get() and drm_*_put() and should not be
used by new code. So convert all users of compatibility functions to
use the new APIs.

Generated by: scripts/coccinelle/api/drm-get-put.cocci

Signed-off-by: Cihangir Akturk <cakturk@gmail.com>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1502454794-28558-5-git-send-email-cakturk@gmail.com
diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
index 9052ebe..0cd827e 100644
--- a/drivers/gpu/drm/ast/ast_fb.c
+++ b/drivers/gpu/drm/ast/ast_fb.c
@@ -266,7 +266,7 @@
 	drm_fb_helper_unregister_fbi(&afbdev->helper);
 
 	if (afb->obj) {
-		drm_gem_object_unreference_unlocked(afb->obj);
+		drm_gem_object_put_unlocked(afb->obj);
 		afb->obj = NULL;
 	}
 	drm_fb_helper_fini(&afbdev->helper);