Check if `ZEX_NUMBER_OF_CCS` env variable provided by the user is
correct. If it isn't then return false and print debug message.
After this change if `zeInit` is called with invalid
`ZEX_NUMBER_OF_CCS`, then it fails with `ZE_RESULT_ERROR_UNINITIALIZED`.
Related-To: NEO-15230, GSD-11251
Signed-off-by: Kindracki, Jakub Tomasz <jakub.tomasz.kindracki@intel.com>