pex-win32.c (pex_win32_exec_child): Only close original file descriptors if child is launched successfully.

2012-07-26  Kazu Hirata  <kazu@codesourcery.com>
	    Sandra Loosemore  <sandra@codesourcery.com>

	libiberty/
	* pex-win32.c (pex_win32_exec_child): Only close original file
	descriptors if child is launched successfully.

Co-Authored-By: Sandra Loosemore <sandra@codesourcery.com>

From-SVN: r189901