MFC 292409:

MFC 292409:
It seems certain Intel GPUs use GPIO bitbanging over a child device
instead of GMBUS access for I2C transfers.  The GMBUS driver falls back
to this mode when a transfer times out.  However, the first transfer to
timeout was sending the request back to itself resulting in an panic due
to recursing on a lock.  Fix it to forward the request on to the proper
device.  This appears to have been accidentally changed in r277487.