Some gcc -W cleanup

clients/tools/ldapdelete.c

clients/tools/ldapmodify.c

clients/tools/ldapmodrdn.c

clients/tools/ldapsearch.c

libraries/liblber/decode.c

libraries/liblber/io.c

libraries/libldap/error.c

libraries/libldap/options.c

libraries/libldap/result.c

libraries/libldap/sort.c

libraries/libldap/tmplout.c

libraries/libldbm/ldbm.c

libraries/libldif/line64.c

libraries/liblutil/base64.c