kbuild: scripts/ver_linux : correct printing of binutils version

Currently scripts/ver_linux prints "Binutils" or other random
information for the version number in the "binutils" output line
on some distributions. This patch corrects that.

When I initially submitted a patch to correct that, I was not aware
that the output from "ld -v" could differ as much as it turned out
it can, so my original fix turned out to not cover all bases.
This patch works correctly with all the different "ld -v" output
that people posted in replys to my first patch, so it should be a
clear win over what we have currently.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>