10075 make usr/src/tools smatch clean

@@ -1,9 +1,10 @@
 #
 # Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 # Use is subject to license terms.
 #
+# Copyright (c) 2018, Joyent, Inc.
 
 PROG=           zic
 
 OBJS=           ialloc.o \
                 scheck.o \

@@ -10,5 +11,7 @@
                 zic.o
 SRCS=           $(OBJS:%.o=%.c)
 
 CERRWARN +=     -_gcc=-Wno-unused-variable
 CERRWARN +=     -_gcc=-Wno-uninitialized
+
+SMOFF +=        signed