drm/i915/selftest: Unify use of intel_remapped_plane_info in igt_vma_rotate_remap()

Always use the modified copy of the intel_remapped_plane_info variables.
An upcoming patch updates the dst_stride field in these copies after
which we can't use the original versions.

v2: Init view in igt_vma_rotate_remap() when declaring it. (Ville)

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/20210325214808.2071517-22-imre.deak@intel.com