Needed for com_err library testing.

* test_et.c [HAVE_SYS_ERRLIST]: Do declare sys_nerr.


To generate a diff of this commit:



	cvs diff -r5.128 -r5.129 krb5/src/util/et/ChangeLog
	cvs diff -r5.5 -r5.6 krb5/src/util/et/test_et.c