12312 fix unused lib dependencies

*** 21,31 ****
  #
  #
  # Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  # Use is subject to license terms.
  #
! # Copyright (c) 2018, Joyent, Inc.
  
  include         ../Makefile.cmd
  
  PROG =          oawk
  LINKPROG =      awk
--- 21,31 ----
  #
  #
  # Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  # Use is subject to license terms.
  #
! # Copyright 2020 Joyent, Inc.
  
  include         ../Makefile.cmd
  
  PROG =          oawk
  LINKPROG =      awk
*** 56,66 ****
  CLEANFILES =    proctab.c y.tab.h y.tab.c awk.h awk.g.c         \
                  tmptoken.c awk.lx.c $(NATIVEOBJS) $(MAKEPRCTAB) \
                  temp
  
  YFLAGS =        -d
- XLDLIBS5CC +=   -lm
  LDLIBS +=       -lm
  CPPFLAGS =      -I. $(CPPFLAGS.master)
  CPPFLAGS +=     -D_FILE_OFFSET_BITS=64
  
  ROOTLINK =      $(LINKPROG:%=$(ROOTBIN)/%)
--- 56,65 ----