arm64/mm: fold check for KFENCE into can_set_direct_map()

arm64/mm: fold check for KFENCE into can_set_direct_map()

KFENCE requires linear map to be mapped at page granularity, so that it
is possible to protect/unprotect single pages, just like with
rodata_full and DEBUG_PAGEALLOC.

Instead of repating

	can_set_direct_map() || IS_ENABLED(CONFIG_KFENCE)

make can_set_direct_map() handle the KFENCE case.

This also prevents potential false positives in kernel_page_present()
that may return true for non-present page if CONFIG_KFENCE is enabled.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20220921074841.382615-1-rppt@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>