Use AC_SEARCH_LIBS instead of AC_CHECK_LIB when

looking for libnsl, so we don't pick it up unless it really is
needed.

Rev: configure.ac:1.18

configure.ac

@@ -441,11 +441,14 @@ fi
 
 AC_CHECK_LIB(crypt, crypt)
 AC_CHECK_LIB(xnet, inet_addr)
-AC_CHECK_LIB(nsl, gethostbyname)
 AC_CHECK_LIB(socket, setsockopt)
 # logwtmp is also in libutil
 AC_CHECK_LIB(util, openpty)
 
+# glibc has a nis-library "libnsl", which we don't need. So use
+# AC_SEARCH_LIBS rather than AC_CHECK_LIB.
+AC_SEARCH_LIBS(gethostbyname, nsl)
+
 # This macro is new in autoconf-2.13
 AC_SEARCH_LIBS(syslog, bsd socket inet, [AC_DEFINE(HAVE_SYSLOG)])