ring-buffer: Remove unused function __rb_data_page_index()

This fixes the following warning when building with clang:

kernel/trace/ring_buffer.c:1842:1: error: unused function
'__rb_data_page_index' [-Werror,-Wunused-function]

Link: http://lkml.kernel.org/r/[e-mail]

Reviewed-by: Douglas Anderson <[e-mail]>
Signed-off-by: Matthias Kaehlcke <[e-mail]>
Signed-off-by: Steven Rostedt (VMware) <[e-mail]>

kernel/trace/ring_buffer.c

···
 }
 EXPORT_SYMBOL_GPL(ring_buffer_change_overwrite);
 
-static __always_inline void *
-__rb_data_page_index(struct buffer_data_page *bpage, unsigned index)
-{
-	return bpage->data + index;
-}
-
 static __always_inline void *__rb_page_index(struct buffer_page *bpage, unsigned index)
 {
 	return bpage->page->data + index;