drm/amdkfd: Initialize SDMA activity counter to 0

To prevent reporting erroneous SDMA usage, initialize SDMA
activity counter to 0 before using.
Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -270,6 +270,7 @@ static ssize_t kfd_procfs_show(struct kobject *kobj, struct attribute *attr,
 					kfd_sdma_activity_worker);
 
 		sdma_activity_work_handler.pdd = pdd;
+		sdma_activity_work_handler.sdma_activity_counter = 0;
 
 		schedule_work(&sdma_activity_work_handler.sdma_activity_work);