features/map: handle syscall errors using switch statement
features/map: handle syscall errors using switch statement

- Removed naked error comparison to ErrNotSupported (although valid)
- Converted error handling logic to switch statement so only a single case may fire.
  Before, it was possible to hit multiple cases if the error from BPFMapCreate
  contained multiple wrapped errors.
- Skipped wrapping of EPERM to avoid ending up with 'unexpected error during feature probe:
  operation not permitted'. Permission errors are not unexpected.

Signed-off-by: Timo Beckers <98c2d5a1e48c998bd9ba9dbc53d6857beae1c9bd@isovalent.com>

cilium/ebpf,cilium/ebpf