Thanks for the explanation, Abhishek Bhadraja.
I determined that it is necessary to establish usPatchesAvailableAtHost = 1 empirically. And it worked.
Mukunthan KAndasamy, the sample code you can find on TI download page http://processors.wiki.ti.com/index.php/CC3000_Wi-Fi_Downloads#CC3000_Wi-Fi_Downloads
My code above is part of the 1.10.1 patch programmer for the Stellaris Cortex M4. The main change in the code: using functions wlan_start (1) [in the TI example wlan_start (0)] to restore the service pack 1.5 and then burn firmware 1.10.1