runqemu: Handle device names like tapX@NONE

ip list can return devices in the form tapX@NONE. If it does so,
ensure we handle that case correctly. Newer distros appear to do
this in some cases.

[YOCTO #8129]

(From OE-Core rev: 6459dde380febce24d2c355d441d9cb3b14409b9)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/runqemu-internal

@@ -179,7 +179,7 @@ else
                exit 1
         fi
 
-        POSSIBLE=`$IFCONFIG link | grep 'tap' | awk '{print $2}' | sed s/://`
+        POSSIBLE=`$IFCONFIG link | grep 'tap' | awk '{print $2}' | sed -e 's/://' -e 's/@.*//'`
         TAP=""
         LOCKFILE=""
         USE_PRECONF_TAP="no"