Workaround kernel bug 50351

[evgeni]

https://bugzilla.kernel.org/show_bug.cgi?id=50351

[evgeni]

Should not happen when called with --background, as we sleep on errors while starting up here.
Happens only when hdaps.ko is loaded very shortly before hdapsd tries to read the position. Like when it is loaded by hdapsd.

[evgeni]

merged into master in 701b71e