driver, toplevel: Avoid emitting the version information twice.

driver, toplevel: Avoid emitting the version information twice.

For a regular compile job, with -v we emit the GCC version information
twice - once from main() and once from process_options().

We do not need to output the second header.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
gcc/ChangeLog:

	* toplev.cc (toplev::main): Only print the version information header
	from toplevel main().