alpha, exec: remove redundant set_fs(USER_DS)

The address limit is already set in flush_old_exec() so this
set_fs(USER_DS) is redundant.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/kernel/process.c

@@ -200,7 +200,6 @@ show_regs(struct pt_regs *regs)
 void
 start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
 {
-	set_fs(USER_DS);
 	regs->pc = pc;
 	regs->ps = 8;
 	wrusp(sp);