10080 smatch Makefile changes for usr/src/cmd

*** 21,30 ****
--- 21,31 ----
  #
  #
  # Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  # Use is subject to license terms.
  #
+ # Copyright (c) 2018, Joyent, Inc.
  
  FSTYPE=         ufs
  LIBPROG=        df
  ATTMK=          $(LIBPROG)
  
*** 38,47 ****
--- 39,51 ----
  CERRWARN +=     -_gcc=-Wno-implicit-function-declaration
  CERRWARN +=     -_gcc=-Wno-parentheses
  CERRWARN +=     -_gcc=-Wno-unused-label
  CERRWARN +=     -_gcc=-Wno-unused-function
  
+ # not linted
+ SMATCH=off
+ 
  # for messaging catalogue file
  #
  POFILE= df.po
  XGETFLAGS += -a -x df.xcl