UPSTREAM: core/service: Fix failing to connect external profile

When initiating a connection to a external profile btd_service_connect
will be called which will change the service state to
BTD_SERVICE_STATE_CONNECTING but then once the connection completes
service_accept is called but since it now checks the state it would
return -EALREADY to prevent driver accept to be called more than once.

BUG=chromium:549436

Change-Id: I26fc5ef9e6c6da13fe69740abf6ed895b6d6ab06
Reviewed-on: https://chromium-review.googlesource.com/310211
Commit-Ready: Jakub x Jakub Pawlowski <jpawlowski@chromium.org>
Tested-by: Jakub x Jakub Pawlowski <jpawlowski@chromium.org>
Reviewed-by: Hsinyu Chao <hychao@chromium.org>
Reviewed-by: Jakub x Jakub Pawlowski <jpawlowski@chromium.org>
diff --git a/src/service.c b/src/service.c
index 2ed72fb..7da922c 100644
--- a/src/service.c
+++ b/src/service.c
@@ -191,7 +191,7 @@
 		break;
 	case BTD_SERVICE_STATE_CONNECTING:
 	case BTD_SERVICE_STATE_CONNECTED:
-		return -EALREADY;
+		return 0;
 	case BTD_SERVICE_STATE_DISCONNECTING:
 		return -EBUSY;
 	}