ver_linux: libc, input redirection to sed fails in some distros

The current implementation has been found not to work across all distros.

The proposed implementation relies on 'sed' to both output the string
'Linux C Library' as well as to open '/proc/self/maps' without having
to use output redirection.

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>