Fix "already done" test in libname_to_filename()
Fix "already done" test in libname_to_filename()

if "(libname == '\0')" should be instead "if (libname != '\0')"

mingodad/tinycc,Archs/TinyCC,code4game/tinycc,Wallbraker/DCPU-TCC,run4flat/tinycc,mitake/tinycc,melkior/tinycc,shinh/nacltcc,alfonsokim/tinycc,rchandramouli/tinycc,FriedBreakfast/tcc,acook/tinycc,metaeducation/tcc,run4flat/tinycc,Wallbraker/DCPU-TCC,mirror/tinycc,avih/tinycc,mingodad/tinycc,fstudio/tinycc,metaeducation/tcc,alfonsokim/tinycc,soywiz/tinycc,soywiz/tinycc,mirror/tinycc,Saectar/inherpreter,ftdi-paul-jiao/tinyCC,andrewchambers/tccmirror,rchandramouli/tinycc,mingodad/tinycc,FriedBreakfast/tcc,shinh/nacltcc,FriedBreakfast/tcc,ftdi-paul-jiao/tinyCC,mitake/tinycc,ftdi-paul-jiao/tinyCC,mitake/tinycc,mobiphil/tinnycc,Saectar/inherpreter,Archs/TinyCC,soywiz/tinycc,mobiphil/tinnycc,Saectar/inherpreter,mirror/tinycc,andrewchambers/tccmirror,metaeducation/tcc,seyko2/tinycc,seyko2/tinycc,leeduhem/tinycc,FriedBreakfast/tcc,mobiphil/tinnycc,fstudio/tinycc,code4game/tinycc,andreiw/tinycc,mirror/tinycc,seyko2/tinycc,mobiphil/tinnycc,acook/tinycc,melkior/tinycc,leeduhem/tinycc,Saectar/inherpreter,gfwilliams/tinycc,andreiw/tinycc,melkior/tinycc,andreiw/tinycc,run4flat/tinycc,acook/tinycc,metaeducation/tcc,run4flat/tinycc,xcm/tcc,leeduhem/tinycc,metaeducation/tcc,yousong/tinycc,fstudio/tinycc,Archs/TinyCC,rchandramouli/tinycc,FriedBreakfast/tcc,xcm/tcc,Wallbraker/DCPU-TCC,mitake/tinycc,xcm/tcc,avih/tinycc,melkior/tinycc,mingodad/tinycc,shinh/nacltcc,Archs/TinyCC,alfonsokim/tinycc,yousong/tinycc,gfwilliams/tinycc,rchandramouli/tinycc,acook/tinycc,alfonsokim/tinycc,andrewchambers/tccmirror,andrewchambers/tccmirror,gfwilliams/tinycc,shinh/nacltcc,Saectar/inherpreter,avih/tinycc,leeduhem/tinycc,andrewchambers/tccmirror,fstudio/tinycc,code4game/tinycc,ftdi-paul-jiao/tinyCC,run4flat/tinycc,alfonsokim/tinycc,yousong/tinycc,gfwilliams/tinycc,Archs/TinyCC,seyko2/tinycc,melkior/tinycc,avih/tinycc,fstudio/tinycc,gfwilliams/tinycc,yousong/tinycc,soywiz/tinycc,seyko2/tinycc,shinh/nacltcc,rchandramouli/tinycc,leeduhem/tinycc