i40evf: don't wait so long

We really don't need to delay an entire millisecond just to get into our
critical section. A microsecond will be sufficient, thank you.

Change-ID: I2d02ece6610007d98cabcb3f42df9a774bb54e59
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40evf/i40evf_main.c

@@ -768,7 +768,7 @@ i40evf_mac_filter *i40evf_add_filter(struct i40evf_adapter *adapter,
 
 	while (test_and_set_bit(__I40EVF_IN_CRITICAL_TASK,
 				&adapter->crit_section))
-		mdelay(1);
+		udelay(1);
 
 	f = i40evf_find_filter(adapter, macaddr);
 	if (NULL == f) {
@@ -840,7 +840,7 @@ static void i40evf_set_rx_mode(struct net_device *netdev)
 
 	while (test_and_set_bit(__I40EVF_IN_CRITICAL_TASK,
 				&adapter->crit_section))
-		mdelay(1);
+		udelay(1);
 	/* remove filter if not in netdev list */
 	list_for_each_entry_safe(f, ftmp, &adapter->mac_filter_list, list) {
 		bool found = false;