fixed USB context index checking
fixed USB context index checking

myriadrf/LimeSuite,limemicro/lms7suite,myriadrf/LimeSuite,myriadrf/LimeSuite,romeojulietthotel/LimeSuite,limemicro/lms7suite,myriadrf/LimeSuite,limemicro/lms7suite,romeojulietthotel/LimeSuite,limemicro/lms7suite,romeojulietthotel/LimeSuite,myriadrf/LimeSuite,romeojulietthotel/LimeSuite,limemicro/lms7suite,romeojulietthotel/LimeSuite