amd/amdkfd: fix a kfd_process ref leak

This patch is to fix a kfd_prcess ref leak.

Signed-off-by: Yifan Zhang <yifan1.zhang@amd.com>
Reviewed-by: Philip Yang <Philip.Yang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: yifancom

drivers/gpu/drm/amd/amdkfd/kfd_events.c

@@ -1350,6 +1350,7 @@ void kfd_signal_poison_consumed_event(struct kfd_node *dev, u32 pasid)
 	user_gpu_id = kfd_process_get_user_gpu_id(p, dev->id);
 	if (unlikely(user_gpu_id == -EINVAL)) {
 		WARN_ONCE(1, "Could not get user_gpu_id from dev->id:%x\n", dev->id);
+		kfd_unref_process(p);
 		return;
 	}