* misc/bits/syslog.h: New file.

* misc/bits/syslog.h: New file.

	* misc/sys/syslog.h: Include <bits/syslog.h> for fortification.
	* misc/Makefile (headers): Add bits/syslog.h.
	* include/sys/syslog.h: Add __vsyslog_chk prototype and hidden_proto.
	* sysdeps/generic/syslog.c: Change vsyslog function to __vsyslog_chk.
	Call __vfprintf_chk if necessary.  Make vsyslog a wrapper.  Add
	__syslog_chk.
	* misc/Versions: Export __syslog_chk and __vsyslog_chk.

	* nis/nis_xdr.c: Help gcc to avoid generating unnecessary wrapper
	functions.