stdio_sync_filebuf.h: Don't include the whole <fstream>, only <streambuf> and <cstdio>.

2003-10-04  Paolo Carlini  <pcarlini@unitus.it>
	    Petur Runolfsson  <peturr02@ru.is>

	* include/ext/stdio_sync_filebuf.h: Don't include the whole
	<fstream>, only <streambuf> and <cstdio>.

Co-Authored-By: Petur Runolfsson <peturr02@ru.is>

From-SVN: r72090