FROMGIT: avdtp: Fix crashes in avdtp_abort

In avdtp_abort, if setup->stream is NULL, trying to access
stream->lsep will crash.

(cherry picked from commit 622d98afbb4f147d0ead1961c80406072bc45aa7
git://git.kernel.org/pub/scm/bluetooth/bluez.git master)

BUG=b:150714532
TEST=run connect-disconnect loop with Parrot Zik 3 on Kindred.
Bluetoohd crashed within ~20 iterations before this change.
There is no crash in 100 iterations after this change.

Change-Id: I7ac724dfd593d422ec6ebb341f0da83fda3aca49
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/bluez/+/2119972
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Sonny Sasaka <sonnysasaka@chromium.org>
Commit-Queue: Yun-Hao Chung <howardchung@google.com>
Tested-by: Yun-Hao Chung <howardchung@google.com>
1 file changed