utils: crc: fix build with big-endian architectures and 1-byte objects
utils: crc: fix build with big-endian architectures and 1-byte objects

crc has some code to reverse endianness on big-endian machines, but does
not handle the case of a 1-byte object (which doesn't need any adjustement).
This causes clang to complain that the switch statement doesn't handle that
case.

Fix by adding a no-op case.

Closes #8269

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla