Simplify linux_exec_setregs() by not duplicating exec_setregs().
No functional changes intended.
I do not like it. It makes changes to exec_setregs() to suddenly affect linuxolator.
In other review, you stop using native set_retval() in linux variant. So why move in reverse direction there ?
If so inclined extract the absolutely common code into some neutrally-named function and call it both from linux_exec_setregs() and exec_setregs().