unicore32: unobfuscate _TIF_WORK_MASK

bits 3..7 in flags are never set there, so this 0xff is pointless
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/unicore32/include/asm/thread_info.h

@@ -146,7 +146,8 @@ static inline struct thread_info *current_thread_info(void)
 /*
  * Change these and you break ASM code in entry-common.S
  */
-#define _TIF_WORK_MASK		0x000000ff
+#define _TIF_WORK_MASK \
+	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME)
 
 #endif /* __KERNEL__ */
 #endif /* __UNICORE_THREAD_INFO_H__ */