ftrace: fix unlocking of hash

This must be brown paper bag week for Steven Rostedt!

While working on ftrace for PPC, I discovered that the hash locking done
when CONFIG_FTRACE_MCOUNT_RECORD is not set, is totally incorrect.

With a cut and paste error, I had the hash lock macro to lock for both
hash_lock _and_ hash_unlock!

This bug did not affect x86 since this bug was introduced when
CONFIG_FTRACE_MCOUNT_RECORD was added to x86.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/trace/ftrace.c

@@ -170,7 +170,8 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
  */
 static DEFINE_SPINLOCK(ftrace_hash_lock);
 #define ftrace_hash_lock(flags)	  spin_lock_irqsave(&ftrace_hash_lock, flags)
-#define ftrace_hash_unlock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags)
+#define ftrace_hash_unlock(flags) \
+			spin_unlock_irqrestore(&ftrace_hash_lock, flags)
 #else
 /* This is protected via the ftrace_lock with MCOUNT_RECORD. */
 #define ftrace_hash_lock(flags)   do { (void)(flags); } while (0)