[GAS] change of ELF flags initial value in rx-linux

[Nick Clifton]

Hi Gunther,

> Setting the value of elf_flags every time in md_parse_option is not necessary.

Actually it is worse than that - it is a bug.  Since md_parse_option is called
for each option on the command line, initialising elf_flags at the start will
undo any changes made to this variable by previous command line options...

> gas/ChangeLog
> 2020-05-XX  Gunther Nikl <gnikl@justmail.de>
> 
> 	* config/tc-rx.c (elf_flags): Initialize for non-linux targets.
> 	  (md_parse_option): Remove initialization of elf_flags.

Approved and applied.

Cheers
  Nick