unicore32, 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: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>

arch/unicore32/include/asm/processor.h

@@ -53,7 +53,6 @@ struct thread_struct {
 #define start_thread(regs, pc, sp)					\
 ({									\
 	unsigned long *stack = (unsigned long *)sp;			\
-	set_fs(USER_DS);						\
 	memset(regs->uregs, 0, sizeof(regs->uregs));			\
 	regs->UCreg_asr = USER_MODE;					\
 	regs->UCreg_pc = pc & ~1;	/* pc */                        \