hypervisor: Revisit Coverity issues regarding cpumap

hypervisor: Revisit Coverity issues regarding cpumap

Turns out the issue regarding ptr_arith and sign_exension weren't false
positives. When shifting an 'unsigned char' as a target, it gets promoted
to an 'int'; however, that 'int' cannot be shifted 32 bits which was how
the algorithm was written. For the ptr_arith rather than index into the
cpumap, change the to address as necessary and assign directly.