[TEST] ucom detach patch

[Poul-Henning Kamp]

http://phk.freebsd.dk/patch/ucom.patch

This patch should make it safe to remove a ucom serial device no matter
what is going on at the time of removal.

The patch also changes the naming of the devices to give the full
complement of serial facilities, so you will see the following
devices in /dev:

	/dev/ttyU0
	/dev/ttyU0.init
	/dev/ttyU0.lock
	/dev/cuaU0
	/dev/cuaU0.init
	/dev/cuaU0.lock

Please test and report.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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FreeBSD committer       | BSD since 4.3-tahoe
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