cdc-acm: fix BREAK rx code path adding necessary calls

cdc-acm: fix BREAK rx code path adding necessary calls

BugLink: https://bugs.launchpad.net/bugs/1923069
commit 08dff274edda54310d6f1cf27b62fddf0f8d146e upstream.

Counting break events is nice but we should actually report them to
the tty layer.

Fixes: 5a6a62bdb9257 ("cdc-acm: add TIOCMIWAIT")
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/20210311133714.31881-1-oneukum@suse.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>