arm-gen.c: Invalid operator test always false
arm-gen.c: Invalid operator test always false

Invalid operator test is always false in gen_opf for arm (found with
cppcheck). This patch fixes the issue.

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