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 \
*** 10,14 ****
--- 11,17 ----
                  zic.o
  SRCS=           $(OBJS:%.o=%.c)
  
  CERRWARN +=     -_gcc=-Wno-unused-variable
  CERRWARN +=     -_gcc=-Wno-uninitialized
+ 
+ SMOFF +=        signed