Kasan early code is only working on init_mm, remove unneeded pgd
parameter from kasan_copy_shadow and rename it to
kasan_copy_shadow_mapping.
Reviewed-by: NAlexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>