I think your problem will be with the rtl8192cu driver - one of my adaptors uses a chipset that needs this driver and it is very hit and miss for me on OSMC as well, (most of the time it doesn’t work) while another adaptor of mine with a different chipset works perfectly.
Raspbmc uses a much older Kernel than OSMC and it seems this driver is problematic on the newer kernels. We are still working to try to improve wifi driver support so watch this space.
One other thing to be aware of is we have set Ethernet to have priority over Wifi and only allow one active network interface - so if you have your Ethernet cable plugged in (as you do during your dmesg dump) wifi will not be activated. As soon as you unplug the Ethernet cable it should activate wifi however, if the wifi was previously configured.