commonUtility::toHex method missing out of bound access check

[souvik1914581]

commonUtility::toHex method returns hex representation of incoming byte, but does not have an out of bound access check, which can lead to SIGSEGV.

openpower-vpd-parser/vpd-manager/include/utility/common_utility.hpp

Line 47 in 66bd44e

return l_map[i_aByte];