usbmon: drop bogus 0t from usbmon.txt

The example is incorrect: there is no 0t socket (the '1t' format has no
bus number in it). Also, correct the broken sentence for USB Tag.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>