Fix warning about non-void function with no return

remotelinuxruncontrolfactory.cpp(124): warning #1011: missing return statement at end of non-void function "RemoteLinux::Internal::RemoteLinuxRunControlFactory::create"

Technically, the function doesn't reach there, but ICC 14 doesn't know
about it.

Change-Id: Id55f6f33ff7c0eb97dba9af99bf0d34a9c01e191
Reviewed-by: Kurt Pattyn <pattyn.kurt@gmail.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>