x32: Only clear TIF_X32 flag once

Commits bb212724 and d1a797f3 both added a call to
clear_thread_flag(TIF_X32) under set_personality_64bit() - only one is
needed.

Signed-off-by: Bobby Powers <bobbypowers@gmail.com>
Link: http://lkml.kernel.org/r/1330228774-24223-1-git-send-email-bobbypowers@gmail.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/kernel/process_64.c

@@ -510,7 +510,6 @@ void set_personality_64bit(void)
 
 	/* Make sure to be in 64bit mode */
 	clear_thread_flag(TIF_IA32);
-	clear_thread_flag(TIF_X32);
 	clear_thread_flag(TIF_ADDR32);
 	clear_thread_flag(TIF_X32);