drm/i915/selftest: Fix debug message in igt_vma_remapped_gtt()

The expected/found values were swapped in a debug message, fix this up.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210325214808.2071517-4-imre.deak@intel.com