Use attr_valfind instead of value_find_ex to optimize lookups

servers/slapd/aci.c

servers/slapd/acl.c

servers/slapd/attr.c

servers/slapd/back-bdb/compare.c

servers/slapd/back-monitor/compare.c

servers/slapd/back-sql/compare.c

servers/slapd/backend.c

servers/slapd/bconfig.c

servers/slapd/compare.c

servers/slapd/filterentry.c

servers/slapd/overlays/dynlist.c

servers/slapd/overlays/syncprov.c

servers/slapd/schema_check.c

servers/slapd/slap.h

servers/slapd/slapi/slapi_utils.c

servers/slapd/syncrepl.c