udev: make USB device version detection more generic

Apparently some devices do not comply with standards (there is no such
thing as USB version 2.01), but other than that works fine. So take into
account only the major number of bcdUSB field.

Fixes QubesOS/qubes-issues#2158

udev/udev-usb-add-change

@@ -21,17 +21,7 @@ XSNAME=`basename ${DEVPATH} | tr . _`
 #DESC=`python -c "dev='%d-%d' % (int('${BUSNUM}'.lstrip('0')), (int('${DEVNUM}'.lstrip('0'))-1)); from xen.util import vusb_util; print vusb_util.get_usbdevice_info(dev);"`
 DESC="${ID_VENDOR_ID}:${ID_MODEL_ID} ${ID_SERIAL}"
 
-VERSION=`cat /sys/$DEVPATH/version`
-if [ "${VERSION}" = " 1.00" -o "${VERSION}" = " 1.10" ] ; then
-	VERSION=1
-elif [ "${VERSION}" = " 2.00" -o "${VERSION}" = " 2.10" ] ; then
-	VERSION=2
-elif [ "${VERSION}" = " 3.00" -o "${VERSION}" = " 3.10" ] ; then
-	VERSION=3
-else
-	# FIXME: silently ignoring devices with unexpected USB version
-	exit 0
-fi
+VERSION=`cat /sys/$DEVPATH/version | tr -d ' '|cut -f 1 -d .`
 
 # ignore usbip-connected devices, as most likely already passed through from
 # another VM