udev: exclude MD from block device ownership event locking

MD instantiates devices at open(). This is incomptible with the
locking logic, as the "change" event emitted when stopping a
device will bring it back.

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>
udevd: add --event-timeout commandline option

Some events take longer than the default 30 seconds. Killing those
events will leave the machine halfway configured.

Add a commandline option '--event-timeout' to handle these cases.

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>
udev: unify event timeout handling

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>
udev: place opening { at the same line as the function declaration

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>
udev: fixup commit dd5eddd28a74a49607a8fffcaf960040dba98479

Commit dd5eddd28a74a49607a8fffcaf960040dba98479 accidentally
removed one line too many.

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>