pds_core: check for work queue before use

Add a check that the wq exists before queuing up work for a
failed devcmd, as the PF is responsible for health and the VF
doesn't have a wq.

Fixes: c2dbb090 ("pds_core: health timer and workqueue")
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230824161754.34264-5-shannon.nelson@amd.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/amd/pds_core/dev.c

@@ -183,7 +183,7 @@ int pdsc_devcmd_locked(struct pdsc *pdsc, union pds_core_dev_cmd *cmd,
 	err = pdsc_devcmd_wait(pdsc, max_seconds);
 	memcpy_fromio(comp, &pdsc->cmd_regs->comp, sizeof(*comp));
 
-	if (err == -ENXIO || err == -ETIMEDOUT)
+	if ((err == -ENXIO || err == -ETIMEDOUT) && pdsc->wq)
 		queue_work(pdsc->wq, &pdsc->health_work);
 
 	return err;