Revert "ring-buffer: Update "shortest_full" in polling"

This reverts commit cf221a78 which is
commit 1e0cb399c7653462d9dadf8ab9425337c355d358 upstream.

It is needed to be dropped due to another conflict that is causing
crashes during Android testing.

Bug: 263508491
Cc: Lee Jones <joneslee@google.com>
Change-Id: I786e1b755a02c6c3b82fa43ec39144a3e270981e
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>