Fix bug in PAN code where no new PAN connections can be made.

If you call PAN_connect() followed quickly by PAN_disconnect(),
you won't be able to establish any additional PANU connections.
This happens because the connection never has a chance to make
it into PAN_STATE_CONNECTED and num_conns only gets decremented
if you disconnect in the connected state. As a result, subsequent
calls to connect will fail because the stack still believes there
to be an existing connection.

Change-Id: Id24873828ca4f517496cb19a44993d0e8e837a1e
Bluetooth: Clear wait flag on Start response.

When remote device does not responds to get capability causing
HAL layer to be blocked hence change is made to clear wait flag
on receiving Start response

Change-Id: I8190742fab18340e3eaa01f748bba26a3d4d17e6
Bluetooth:GAP: Add NULL check before accessing accept socket

Add NULL check before accessing accept_rs variable to
avoid null pointer exception while referring to invalid
memory.

Change-Id: Ibc38d1c2fb19eb171cf136c47248ad8828676ac1