testing: Rename interfaces and bridges so they are easier to identify

This simplifies capturing traffic with Wireshark on the host as each of
the guest's interfaces is clearly identified.
The three bridges were previously numbered starting from 0, this scheme
is restored here.

testing/start-testing

@@ -9,7 +9,7 @@ CONFDIR=$DIR/config/kvm
 KNLSRC=$BUILDDIR/$KERNEL/arch/x86/boot/bzImage
 KNLTARGET=/var/run/kvm-swan-kernel
 HOSTFSTARGET=/var/run/kvm-swan-hostfs
-MCASTBRS="virbr1 virbr2"
+MCASTBRS="test-br0 test-br1"
 
 echo "Starting test environment"
 
@@ -41,7 +41,7 @@ done
 for br in $MCASTBRS
 do
 	cd /sys/devices/virtual/net/$br/brif
-	for vnet in `find . -name "vnet*"`
+	for vnet in `find . -name "*eth?"`
 	do
 		echo 2 > $vnet/multicast_router
 	done