qed: Fix possible memory leak in qed_dcbnl_get_ieee_pfc()

'dcbx_info is malloced in qed_dcbnl_get_ieee_pfc() and should be freed
before leaving from the error handling cases, otherwise it will cause
memory leak.

Fixes: a1d8d8a51e83 ("qed: Add dcbnl support.")
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qed/qed_dcbx.c

@@ -1855,6 +1855,7 @@ static int qed_dcbnl_get_ieee_pfc(struct qed_dev *cdev,
 
 	if (!dcbx_info->operational.ieee) {
 		DP_INFO(hwfn, "DCBX is not enabled/operational in IEEE mode\n");
+		kfree(dcbx_info);
 		return -EINVAL;
 	}