Remove redundant os.close(master_fd) call inside SpawnProcess._start() since
that file discriptor is referenced by a file object which already has an
appropriate close() call. This fixes an 'IOError: [Errno 9] Bad file
descriptor' exception which was raised when attempting to close the file

svn path=/main/trunk/; revision=11666
diff --git a/pym/_emerge/ b/pym/_emerge/
index 65093dd..7b4067a 100644
--- a/pym/_emerge/
+++ b/pym/_emerge/
@@ -2142,7 +2142,6 @@
 		if isinstance(retval, int):
 			# spawn failed
-			os.close(master_fd)
 			for f in files.values():
 			self.returncode = retval