sched/wait, fs/ocfs2: Convert wait_on_atomic_t() usage to the new wait_var_event() API

The old wait_on_atomic_t() is going to get removed, use the more
flexible wait_var_event() API instead.

No change in functionality.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

fs/ocfs2/filecheck.c

@@ -134,9 +134,10 @@ ocfs2_filecheck_sysfs_free(struct ocfs2_filecheck_sysfs_entry *entry)
 {
 	struct ocfs2_filecheck_entry *p;
 
-	if (!atomic_dec_and_test(&entry->fs_count))
-		wait_on_atomic_t(&entry->fs_count, atomic_t_wait,
-				 TASK_UNINTERRUPTIBLE);
+	if (!atomic_dec_and_test(&entry->fs_count)) {
+		wait_var_event(&entry->fs_count,
+			       !atomic_read(&entry->fs_count));
+	}
 
 	spin_lock(&entry->fs_fcheck->fc_lock);
 	while (!list_empty(&entry->fs_fcheck->fc_head)) {
@@ -183,7 +184,7 @@ static void
 ocfs2_filecheck_sysfs_put(struct ocfs2_filecheck_sysfs_entry *entry)
 {
 	if (atomic_dec_and_test(&entry->fs_count))
-		wake_up_atomic_t(&entry->fs_count);
+		wake_up_var(&entry->fs_count);
 }
 
 static struct ocfs2_filecheck_sysfs_entry *