kernel/time/timekeeping.c: cleanups

- remove the no longer required __attribute__((weak)) of xtime_lock
- remove the following no longer used EXPORT_SYMBOL's:
  - xtime
  - xtime_lock

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/time.h

@@ -92,7 +92,7 @@ static inline struct timespec timespec_sub(struct timespec lhs,
 
 extern struct timespec xtime;
 extern struct timespec wall_to_monotonic;
-extern seqlock_t xtime_lock __attribute__((weak));
+extern seqlock_t xtime_lock;
 
 extern unsigned long read_persistent_clock(void);
 extern int update_persistent_clock(struct timespec now);

kernel/time/timekeeping.c

@@ -24,9 +24,7 @@
  * This read-write spinlock protects us from races in SMP while
  * playing with xtime and avenrun.
  */
-__attribute__((weak)) __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
-
-EXPORT_SYMBOL(xtime_lock);
+__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
 
 
 /*
@@ -47,7 +45,6 @@ EXPORT_SYMBOL(xtime_lock);
 struct timespec xtime __attribute__ ((aligned (16)));
 struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
 static unsigned long total_sleep_time;		/* seconds */
-EXPORT_SYMBOL(xtime);
 
 static struct timespec xtime_cache __attribute__ ((aligned (16)));
 static inline void update_xtime_cache(u64 nsec)