lib/crc: crc32: Change crc32() from macro to inline function and remove cast

lib/crc: crc32: Change crc32() from macro to inline function and remove cast

There's no need for crc32() to be a macro.  Make it an inline function
instead.  Also, remove the cast of the data pointer to
'unsigned char const *', which is no longer necessary now that the type
used in the function prototype is 'const void *'.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250619183414.100082-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>