luci-mod-status: channel_analysis: correct VHT 20/40 MHz center chann…

…els (openwrt#6728)

* luci-mod-status: add missing vht40 channels

As of now, channel_analysis is missing 40 MHz VHT channels. 
What it does for those right now is
display them as 20 MHz channels (both in the plot and the table below),
but it uses the center frequency of the 40 MHz channel, which means
their (wrong) 20 MHz band in the plot is offset by 2.

This fixes openwrt#6419. Note that this only occurs for **other** stations.
The code for local_wifi is different and already complete.

Signed-off-by: Frank Löffler <[email protected]>

modules/luci-mod-status/htdocs/luci-static/resources/view/status/channel_analysis.js

@@ -289,7 +289,10 @@ return view.extend({
 						}
 					}
 
-				if (res.vht_operation != null) {
+				/* if channel_width <= 40, refer to HT (above) for actual channel width,
+				 * as vht_operation.channel_width == 40 really only means that the used
+				 * bandwidth is <= 40 and could be 20 Mhz as well */
+				if (res.vht_operation != null && res.vht_operation.channel_width > 40) {
 					center_channels[0] = res.vht_operation.center_freq_1;
 					if (res.vht_operation.channel_width == 80) {
 						chan_width = 8;