cacheinfo: Align checks in cache_shared_cpu_map_{setup,remove} for readability

The checks to skip the CPU itself or no cacheinfo case are implemented
bit differently though the effect is exactly same. Just align the
implementation in both cache_shared_cpu_map_{setup,remove} just for
improved readability. No functional change.

Link: https://lore.kernel.org/r/20220704101605.1318280-9-sudeep.holla@arm.com


Tested-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>