ring-buffer: rb_is_reader_page() can return boolean

Make rb_is_reader_page() return bool to improve readability due to this
particular function only using either true or false as its return value.

No functional change.

Link: http://lkml.kernel.org/r/1443537816-5788-4-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index fc347f8..26a948f 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -829,7 +829,7 @@
  * writer is ever on it, the previous pointer never points
  * back to the reader page.
  */
-static int rb_is_reader_page(struct buffer_page *page)
+static bool rb_is_reader_page(struct buffer_page *page)
 {
 	struct list_head *list = page->list.prev;