Bluetooth: OBEX: Don't close transport when obex is disconnected

Precondition: PTS 7.0

Usecase:
Execute test case TC_TG_CA_BI_02_C for AVRCP 1.6

Expectation:
Test case should pass

Observation:
Test case fails

Root cause:
Disconnection of OBEX from PTS leads to disconnection of transport
(initiated by DUT) leading to test case failure. Obex server was
unnecessary assuming that transport would be disconnected so was
informing registered users that transport has been disconnected,
which was leading to issues on new obex connect on same transport
channel from remote obex client

Fix:
Remove check to break out of loop after obex disconnection, as that is
already handled in case when read would return -1 in case transport
is closed.

Test: TC_TG_CA_BI_02_C can be passed after the patch.

Bug: 35590000
Change-Id: Ic1682ce77c07cf2e43da09dc95fff2214338f758