[media] drx-j: avoid calling power_down_foo twice

When switching from one video standard to another one,
power_down_vsb is called twice. Well, as the device is already
in power_down mode, the second call always fail. This causes that
any subsequent frontend set to fail as well:

[145074.501243] drx39xyj:power_down_vsb: called
[145089.195396] drx39xyj:power_down_vsb: error -5
[145089.195404] drx39xyj:ctrl_set_standard: error -5
[145089.195417] drx39xyj:drx39xxj_set_frontend: Failed to set standard! result=fffffffb
[145089.195470] drx39xyj:ctrl_sig_quality: error -5
[145089.195473] drx39xyj:drx39xxj_read_ber: drx39xxj: could not get ber!
[145089.195475] drx39xyj:ctrl_sig_quality: error -5
[145089.195477] drx39xyj:drx39xxj_read_signal_strength: drx39xxj: could not get signal strength!
[145089.195479] drx39xyj:ctrl_sig_quality: error -5
[145089.195480] drx39xyj:drx39xxj_read_snr: drx39xxj: could not read snr!
[145089.195482] drx39xyj:ctrl_sig_quality: error -5
[145089.195484] drx39xyj:drx39xxj_read_ucblocks: drx39xxj: could not get uc blocks!
[145089.195498] drx39xyj:ctrl_sig_quality: error -5
[145089.195500] drx39xyj:drx39xxj_read_ber: drx39xxj: could not get ber!
[145089.195502] drx39xyj:ctrl_sig_quality: error -5
[145089.195503] drx39xyj:drx39xxj_read_signal_strength: drx39xxj: could not get signal strength!
[145089.195505] drx39xyj:ctrl_sig_quality: error -5
[145089.195506] drx39xyj:drx39xxj_read_snr: drx39xxj: could not read snr!
[145089.195508] drx39xyj:ctrl_sig_quality: error -5
[145089.195510] drx39xyj:drx39xxj_read_ucblocks: drx39xxj: could not get uc blocks!
[145090.196291] drx39xyj:drx39xxj_read_status: drx39xxj: could not get lock status!
[145090.196508] drx39xyj:ctrl_sig_quality: error -5
[145090.196511] drx39xyj:drx39xxj_read_ber: drx39xxj: could not get ber!
[145090.196514] drx39xyj:ctrl_sig_quality: error -5
[145090.196515] drx39xyj:drx39xxj_read_signal_strength: drx39xxj: could not get signal strength!
[145090.196518] drx39xyj:ctrl_sig_quality: error -5
[145090.196519] drx39xyj:drx39xxj_read_snr: drx39xxj: could not read snr!
[145090.196522] drx39xyj:ctrl_sig_quality: error -5
[145090.196523] drx39xyj:drx39xxj_read_ucblocks: drx39xxj: could not get uc blocks!
[145090.196553] drx39xyj:ctrl_sig_quality: error -5
[145090.196554] drx39xyj:drx39xxj_read_ber: drx39xxj: could not get ber!
[145090.196557] drx39xyj:ctrl_sig_quality: error -5
[145090.196558] drx39xyj:drx39xxj_read_signal_strength: drx39xxj: could not get signal strength!
[145090.196560] drx39xyj:ctrl_sig_quality: error -5
[145090.196562] drx39xyj:drx39xxj_read_snr: drx39xxj: could not read snr!
[145090.196564] drx39xyj:ctrl_sig_quality: error -5
[145090.196565] drx39xyj:drx39xxj_read_ucblocks: drx39xxj: could not get uc blocks!
[145091.119265] drx39xyj:ctrl_sig_quality: error -5
[145091.119271] drx39xyj:drx39xxj_read_ber: drx39xxj: could not get ber!
[145091.119274] drx39xyj:ctrl_sig_quality: error -5
[145091.119276] drx39xyj:drx39xxj_read_signal_strength: drx39xxj: could not get signal strength!
[145091.119278] drx39xyj:ctrl_sig_quality: error -5
[145091.119280] drx39xyj:drx39xxj_read_snr: drx39xxj: could not read snr!
[145091.119282] drx39xyj:ctrl_sig_quality: error -5
[145091.119283] drx39xyj:drx39xxj_read_ucblocks: drx39xxj: could not get uc blocks!

Acked-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/dvb-frontends/drx39xyj/drxj.c

@@ -18264,6 +18264,7 @@ ctrl_power_mode(struct drx_demod_instance *demod, enum drx_power_mode *mode)
 				goto rw_error;
 			}
 		}
+		ext_attr->standard = DRX_STANDARD_UNKNOWN;
 	}
 
 	common_attr->current_power_mode = *mode;