KVM: arm64: Replace ternary flags with str_on_off() helper

Replace repetitive ternary expressions with the str_on_off() helper
function. This change improves code readability and ensures consistency
in tracepoint string formatting

Signed-off-by: Seongsu Park <sgsu.park@samsung.com>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/1891546521.01744691102904.JavaMail.epsvc@epcpadp1new


Signed-off-by: Marc Zyngier <maz@kernel.org>