Change qFatal to qWarning

While the process should terminate immediately with a non-zero exit code
on component error, it does that in the next line already. The main
difference is dropping the backtrace, which is not useful in this case.

Change-Id: I866ea00e62cb9d1b7c506b9819cd9bb2750ac81f
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>