Add support for new USB 3G device.

Submitted by:	gabor@zahemszky.hu
MFC after:	1 week


git-svn-id: svn+ssh://svn.freebsd.org/base/head@273252 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
* Zero rule buffer.
* Rename 'read' variable.

Pointed by:	luigi


git-svn-id: svn+ssh://svn.freebsd.org/base/head@273253 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f