preinit: use grep -q where applicable

SVN-Revision: 19480

target/linux/brcm-2.4/base-files/lib/preinit/05_set_failsafe_switch_brcm

@@ -6,7 +6,7 @@ failsafe_ip() {
 		echo "0 1 2 3 4 ${cpu_port:-5u*}" > /proc/switch/eth0/vlan/0/ports
 	}
 	
-	[ -n "$pi_ifname" ] && grep "$pi_ifname" /proc/net/dev >/dev/null && {
+	[ -n "$pi_ifname" ] && grep -q "$pi_ifname" /proc/net/dev && {
         	ifconfig $pi_ifname $pi_ip netmask $pi_netmask broadcast $pi_broadcast up
         }
 }

target/linux/brcm-2.4/base-files/lib/preinit/15_set_preinit_interface_brcm

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 port_net_echo() {
-	[ -n "$pi_ifname" ] && grep "$pi_ifname" /proc/net/dev >/dev/null && {
+	[ -n "$pi_ifname" ] && grep -q "$pi_ifname" /proc/net/dev && {
 		if [ "$pi_preinit_net_messages" = "y" ] || [ "$pi_failsafe_net_message" = "true" ] && [ "$pi_preinit_no_failsafe_netmsg" != "y" ]; then 
 			netmsg $pi_broadcast "$1"
 		fi
@@ -12,7 +12,7 @@ preinit_ip_deconfig() {
 	if [ -z "$pi_ifname" ]; then
 		ifconfig $ifname 0.0.0.0 down
 	else
-		grep "$pi_ifname" /proc/net/dev >/dev/null && {
+		grep -q "$pi_ifname" /proc/net/dev && {
 			ifconfig $pi_ifname 0.0.0.0 down
 		}
 	fi