udev: Fix parsing of udev.event-timeout kernel parameter.

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>
udev: avoid magic constants in kernel-cmdline parsers

Lets recognize the fact that startswith() returns a pointer to the tail on
success. Use it instead of hard-coding string-lengths as magic constants.

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>
s/commandline/command line/g

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>
man/udev.conf.xml: fix s/commandline/command line/g and rebuild man pages

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