[media] rcar_vin: propagate querystd() error upstream

rcar_vin_set_fmt() defaults to  PAL when the subdevice's querystd() method call
fails (e.g. due to I2C error).  This doesn't work very well when a camera being
used  outputs NTSC which has different order of fields and resolution.  Let  us
stop  pretending and return the actual error except  when the querystd() method
is not implemented,  in which case  we'll have  to set the 'field' variable  to
V4L2_FIELD_NONE.

Note that doing this would prevent video capture on at least Renesas Henninger/
Porter boards where I2C seems particularly buggy.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>