KVM: arm64: vgic-v5: Cast vgic_apr to u32 to avoid undefined behaviours

KVM: arm64: vgic-v5: Cast vgic_apr to u32 to avoid undefined behaviours

Passing a u64 to __builtin_ctz() is odd, and requires some digging to
figure out why this construct is indeed safe as long as the HW is
correct.

But it is much easier to make it clear to the compiler by casting
the u64 into an intermediate u32, and be done with the UD.

Reviewed-by: Sascha Bischoff <sascha.bischoff@arm.com>
Fixes: 933e5288fa971 ("KVM: arm64: gic-v5: Check for pending PPIs")
Link: https://sashiko.dev/#/patchset/20260319154937.3619520-1-sascha.bischoff%40arm.com
Link: https://patch.msgid.link/20260401103611.357092-9-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>