scripts: fix binutils-version.sh

The current binutils-version.sh expects the version string at the end
of the first line.  It turned out to not work with Linaro toolchain:
It has "Linaro 2014.09" at the back.

To fix this issue, let's parse the word right after the close
parenthesis.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reported-by: York Sun <yorksun@freescale.com>
Acked-by: Dirk Behme <dirk.behme@gmail.com>