drm/amdgpu: fix the nullptr issue when reenter GPU recovery

in single gpu system, if driver reenter gpu recovery,
amdgpu_device_lock_adev will return false, but hive is
nullptr now.
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Dennis Li <Dennis.Li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -4371,8 +4371,8 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
 		if (!amdgpu_device_lock_adev(tmp_adev)) {
 			DRM_INFO("Bailing on TDR for s_job:%llx, as another already in progress",
 				  job ? job->base.id : -1);
-			mutex_unlock(&hive->hive_lock);
-			return 0;
+			r = 0;
+			goto skip_recovery;
 		}
 
 		/*
@@ -4505,6 +4505,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
 		amdgpu_device_unlock_adev(tmp_adev);
 	}
 
+skip_recovery:
 	if (hive) {
 		atomic_set(&hive->in_reset, 0);
 		mutex_unlock(&hive->hive_lock);