Since Linux 6.2, the implementation of flush_dcache_page on riscv
references GPL-only symbol `PageHuge`, breaking the build of zfs.
This patch uses existing mechanism to override flush_dcache_page,
removing the call to `PageHuge`. According to comments in kernel,
it is only used to do some check against HugeTLB pages, which only
exist in userspace. ZFS uses flush_dcache_page only on kernel pages,
thus this patch will not introduce any behaviour change.
See also: torvalds/linux@d33deda, openzfs/zfs@589f59b
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Shengqi Chen <harry-chen@outlook.com>
Closes#14974Closes#15627
9ecd112dc1