evdev: Only open /dev/input/event*[0-9] devices

We're not interested in compatibility devices like /dev/input/mice, so
don't open them.

Also, udevd creates temporary files named like <device>.udev-tmp, so only
match devices that end in a number.

Review URL: https://codereview.chromium.org/146823004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247729 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 247729