USB: pegasus error path not resetting task's state

there is an error path in the pegasus driver which can leave
the task in TASK_UNINTERRUPTIBLE. Depending on when it
schedules next, this can be bad.

Signed-off-by: Oliver Neukum <oliver@neukum.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>