KVM: arm64: Fix comment typo in nvhe/switch.c

Fix the comment of __hyp_vgic_restore_state() from saying VEH to VHE,
also change the underscore to a dash to match the comment
above __hyp_vgic_save_state().

Signed-off-by: Wei-Lin Chang <r09922117@csie.ntu.edu.tw>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220929042839.24277-1-r09922117@csie.ntu.edu.tw