ring-buffer: Fix typo in comment about header page pointer

Fix typo in comment about header page pointer in function
rb_get_reader_page.

Link: https://lore.kernel.org/20250118012352.3430519-1-zhouzhouyi@gmail.com
Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Author: zhouzhouyi-hub

kernel/trace/ring_buffer.c

@@ -5318,7 +5318,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	 * moving it. The page before the header page has the
 	 * flag bit '1' set if it is pointing to the page we want.
 	 * but if the writer is in the process of moving it
-	 * than it will be '2' or already moved '0'.
+	 * then it will be '2' or already moved '0'.
 	 */
 
 	ret = rb_head_page_replace(reader, cpu_buffer->reader_page);