KVM: selftests: Fix __GUEST_ASSERT() format warnings in ARM's arch timer test

Use %x instead of %lx when printing uint32_t variables to fix format
warnings in ARM's arch timer test.

aarch64/arch_timer.c: In function ‘guest_run_stage’:
aarch64/arch_timer.c:138:33: warning: format ‘%lx’ expects argument of type ‘long unsigned int’,
                             but argument 6 has type ‘uint32_t’ {aka ‘unsigned int’} [-Wformat=]
  138 |                                 "config_iter + 1 = 0x%lx, irq_iter = 0x%lx.\n"
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
......
  141 |                                 config_iter + 1, irq_iter);
      |                                 ~~~~~~~~~~~~~~~
      |                                             |
      |                                             uint32_t {aka unsigned int}

Fixes: d1dafd06 ("KVM: arm64: selftests: Enable tuning of error margin in arch_timer test")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20240314175116.2366301-1-seanjc@google.com


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>