This change replaces a call to a thick socket operation binding that uses
an exception to report an expected condition (return with EINPROGRESS
error) with a thin call reporting the same information through a return
value and errno setting, to avoid an unnecessary exception raise.

Tested on x86_64-pc-linux-gnu, committed on trunk

2013-04-11  Thomas Quinot  <quinot@adacore.com>

	* g-socket.adb (Connect_Socket, timeout version): Call
	underlying connect operation directly, not through the 2-argument
	Connect_Socket thick binding, in order to avoid raising a junk
	exception for the EINPROGRESS return.