Revert "media: cec: abort if the current transmit was canceled"

This reverts commit b64cb24a which is
commit 590a8e56 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I9b81fc8045cb2bd2788b20a8b66f1307469b719c
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>