ver_linux: util-linux, 'fdformat' not ubiquitous any longer

The current implementation relies on 'fdformat' to output the version of
'util-linux'. This does not seem to be reliable any longer, as 'fdformat'
does not seem to come preinstalled in all ditros these days.

The proposed implementation uses 'mount' to output both the version
of 'util-linux' and 'mount' proper, as 'mount' is also a part of the
'util-linux' package.

Tested on:
Gentoo Linux
Debian 6.0.10
Oracle Linux Server release 7.1

Rely on regex to find the version number, rather than a field number.

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