Turn the generic versions into inline functions and avoid
SKEIN_PORT_CODE trickery.
Also drop the PLATFORM_MUST_ALIGN check for using the fast bcopy
variants. bcopy doesn't assume alignment, and the userspace version is
currently different because the _ALIGNMENT_REQUIRED macro is only
defined by the kernelspace headers.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes#10470