drm/amdkfd: Fix a potential memory leak

Free mqd_mem_obj it GTT buffer allocation for MQD+control stack fails.
Signed-off-by: Oak Zeng <ozeng@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c

@@ -76,6 +76,7 @@ static int init_mqd(struct mqd_manager *mm, void **mqd,
 	struct v9_mqd *m;
 	struct kfd_dev *kfd = mm->dev;
 
+	*mqd_mem_obj = NULL;
 	/* From V9,  for CWSR, the control stack is located on the next page
 	 * boundary after the mqd, we will use the gtt allocation function
 	 * instead of sub-allocation function.
@@ -93,8 +94,10 @@ static int init_mqd(struct mqd_manager *mm, void **mqd,
 	} else
 		retval = kfd_gtt_sa_allocate(mm->dev, sizeof(struct v9_mqd),
 				mqd_mem_obj);
-	if (retval != 0)
+	if (retval) {
+		kfree(*mqd_mem_obj);
 		return -ENOMEM;
+	}
 
 	m = (struct v9_mqd *) (*mqd_mem_obj)->cpu_ptr;
 	addr = (*mqd_mem_obj)->gpu_addr;