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

A case when remote device has disconnected obex connection, but
has still kept the transport (L2CAP/RFCOMM) open. In such cases
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. This patch removes
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.

Change-Id: Ic1682ce77c07cf2e43da09dc95fff2214338f758
CRs-Fixed: 935761