Add libuserdefs and use in cmd/{oamuser,passwd}

@@ -29,11 +29,11 @@
 include ../Makefile.cmd
 
 passwd := LDLIBS += $(ROOT)/usr/lib/passwdutil.so.1 
 lint := LDLIBS += -lpasswdutil
 LDFLAGS += $(ZIGNORE)
-LDLIBS += -lbsm -lpam -lnsl
+LDLIBS += -luserdefs -lbsm -lpam -lnsl
 
 FILEMODE = 06555
 XGETFLAGS += -a -x $(PROG).xcl
 
 .KEEP_STATE: