drm/amd/display: Slightly optimize dm_dmub_outbox1_low_irq()

A kzalloc()+memcpy() can be optimized in a single kmemdup().
This saves a few cycles because some memory doesn't need to be zeroed.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -820,15 +820,14 @@ static void dm_dmub_outbox1_low_irq(void *interrupt_params)
 					DRM_ERROR("Failed to allocate dmub_hpd_wrk");
 					return;
 				}
-				dmub_hpd_wrk->dmub_notify = kzalloc(sizeof(struct dmub_notification), GFP_ATOMIC);
+				dmub_hpd_wrk->dmub_notify = kmemdup(&notify, sizeof(struct dmub_notification),
+								    GFP_ATOMIC);
 				if (!dmub_hpd_wrk->dmub_notify) {
 					kfree(dmub_hpd_wrk);
 					DRM_ERROR("Failed to allocate dmub_hpd_wrk->dmub_notify");
 					return;
 				}
 				INIT_WORK(&dmub_hpd_wrk->handle_hpd_work, dm_handle_hpd_work);
-				if (dmub_hpd_wrk->dmub_notify)
-					memcpy(dmub_hpd_wrk->dmub_notify, &notify, sizeof(struct dmub_notification));
 				dmub_hpd_wrk->adev = adev;
 				if (notify.type == DMUB_NOTIFICATION_HPD) {
 					plink = adev->dm.dc->links[notify.link_index];