KVM: arm64: Drop is_kernel_in_hyp_mode() from __invalidate_icache_guest_page()

KVM: arm64: Drop is_kernel_in_hyp_mode() from __invalidate_icache_guest_page()

It is pretty obvious that is_kernel_in_hyp_mode() doesn't make much
sense in the hypervisor part of KVM, and should be reserved to the
kernel side.

However, mem_protect.c::invalidate_icache_guest_page() calls into
__invalidate_icache_guest_page(), which uses is_kernel_in_hyp_mode().
Given that this is part of the pKVM side of the hypervisor, this
helper can only return true.

Nothing goes really bad, but __invalidate_icache_guest_page() could
spell out what the actual check is: we cannot invalidate the cache
if the i-cache is VPIPT and we're running at EL1.

Drop the is_kernel_in_hyp_mode() check for an explicit check against
CurrentEL being EL1 or not.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230609162200.2024064-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>