ver_linux: proc/modules, limit text processing to 'sed'

This patch is more of a personal preference, rather than a fix for a problem.

The current implementation used a combination of both 'cat' and 'sed'
to generate an unsorted list of kernel modules separated by while space.

The proposed implementation uses 'sort' and 'sed' to generate a sort
list of kernel modules separated by while space.

Tested on:
Gentoo Linux
Debian 6.0.10
Oracle Linux Server release 7.1
Arch Linux
openSuSE 13.2

Signed-off-by: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>