gril: Return error when failing to connect

Return error when failing to connect to socket. The previous behaviour
was exiting the process.
mtk: Retry when failing to connect to rild

Retry when failing to connect to rild to be able to recover if rild is
not ready.
ril: Retry when failing to connect to rild

Retry when failing to connect to rild to be able to recover if rild is
not ready.
Merge pull request #111 from alfonsosanchezbeato/fix-fail-connect

Retry when failing to connect to rild