msm: subsystem_restart: Bypass error ready handler when there is no PIL

If a subsystem is not loaded by PIL, return from the error ready handler
without doing the completion, since PIL doesn't powerup the modem and
there is no thread waiting on the completion.

Change-Id: I5ba30c04c751acc13d85890a4e8fe505d48b6303
Signed-off-by: Seemanta Dutta <seemanta@codeaurora.org>