frv, exec: remove redundant set_fs(USER_DS)

The address limit is already set in flush_old_exec() so those calls to
set_fs(USER_DS) are redundant.

Also removed the dead code in flush_thread().

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/frv/include/asm/processor.h

@@ -97,7 +97,6 @@ extern struct task_struct *__kernel_current_task;
  */
 #define start_thread(_regs, _pc, _usp)			\
 do {							\
-	set_fs(USER_DS); /* reads from user space */	\
 	__frame = __kernel_frame0_ptr;			\
 	__frame->pc	= (_pc);			\
 	__frame->psr	&= ~PSR_S;			\

arch/frv/kernel/process.c

@@ -143,10 +143,7 @@ void machine_power_off(void)
 
 void flush_thread(void)
 {
-#if 0 //ndef NO_FPU
-	unsigned long zero = 0;
-#endif
-	set_fs(USER_DS);
+	/* nothing */
 }
 
 inline unsigned long user_stack(const struct pt_regs *regs)