QtIFW

Make sure we do not fail if we can't create the lock file.

If we can't lock the file (possible missing privileges to create
and lock it), we now check the running processes before we fail.

Task-number: QTIFW-566
Change-Id: I821ccf8c37d6a235df49e060c59a0283bb91261c
Reviewed-by: Takayuki ORITO
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>
Reviewed-by: Niels Weber <niels.weber@digia.com>