Fix up i387 task switching bug introduced by Andi Kleen's patch

to speed it up - use the proper bitmask for clearing "used-fpu"
state.

include/asm-i386/i387.h

@@ -36,7 +36,7 @@ static inline void __save_init_fpu( struct task_struct *tsk )
 		asm volatile( "fnsave %0 ; fwait"
 			      : "=m" (tsk->thread.i387.fsave) );
 	}
-	tsk->thread_info->flags &= ~TIF_USEDFPU;
+	tsk->thread_info->flags &= ~_TIF_USEDFPU;
 }
 
 static inline void save_init_fpu( struct task_struct *tsk )