Fix the "-version" option, which was accidentally broken in commit
fc9c541:
* exit after printing version information rather than proceeding
blithely onward (and likely printing the full usage message)
* correct the cut-n-paste error in the usage message for it
* don't insist on the presence of a following argument for
options which don't take an argument (this was preventing
'qemu-arm -version' from working)
* remove a spurious argc check from the beginning of main() which
meant 'QEMU_VERSION=1 qemu-arm' didn't work.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andrzej Zaborowski <andrew.zaborowski@intel.com>