10080 smatch Makefile changes for usr/src/cmd

*** 10,19 ****
--- 10,20 ----
  #
  
  #
  # Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  # Copyright 2014 Alexander Pyhalov
+ # Copyright (c) 2018, Joyent, Inc.
  #
  
  
  LIBPROG=        mailwrapper
  
*** 47,56 ****
--- 48,59 ----
  
  CPPFLAGS =      -I. $(CPPFLAGS.master)
  
  LINTFLAGS       += -erroff=E_FUNC_RET_ALWAYS_IGNOR2
  
+ SMOFF += all_func_returns
+ 
  # conditional assignments
  #
  all:=           TARGET= all
  install:=       TARGET= install
  clean:=         TARGET= clean