staging: comedi: don't release mutex too early in comedi_auto_config()
`comedi_auto_config()` uses `dev->class_dev` for logging a kernel
message after releasing `dev->mutex`. There is an unlikely possibility
that the Comedi device `dev` will have been removed by the
`COMEDI_DEVCONFIG` ioctl() command. Keep hold of the mutex until the
kernel message has been sent to prevent that. The function can call
`comedi_release_hardware_device()` on error. In that case, the mutex
must be unlocked before that.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>