10080 smatch Makefile changes for usr/src/cmd

*** 22,32 ****
  #
  # Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  # Use is subject to license terms.
  # Copyright (c) 2016, Chris Fraire <cfraire@me.com>.
  #
! # cmd/cmd-inet/usr.sbin/nwamcfg/Makefile
  
  PROG=   nwamcfg
  OBJS=   nwamcfg.o nwamcfg_lex.o nwamcfg_grammar.tab.o
  
  include ../../../Makefile.cmd
--- 22,32 ----
  #
  # Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  # Use is subject to license terms.
  # Copyright (c) 2016, Chris Fraire <cfraire@me.com>.
  #
! # Copyright (c) 2018, Joyent, Inc.
  
  PROG=   nwamcfg
  OBJS=   nwamcfg.o nwamcfg_lex.o nwamcfg_grammar.tab.o
  
  include ../../../Makefile.cmd
*** 42,51 ****
--- 42,53 ----
  CERRWARN +=     -_gcc=-Wno-uninitialized
  CERRWARN +=     -_gcc=-Wno-unused-variable
  CERRWARN +=     -_gcc=-Wno-unused-label
  CERRWARN +=     -_gcc=-Wno-implicit-function-declaration
  
+ SMOFF += all_func_returns
+ 
  .KEEP_STATE:
  
  all: $(PROG)
  
  $(PROG): $(OBJS)