nir: Initialize evaluate_cube_face_index_amd dst.x.
Fix defect reported by Coverity Scan. Uninitialized scalar variable (UNINIT) uninit_use: Using uninitialized value dst.x. Fixes: a1a2a8df ("nir: add AMD_gcn_shader extended instructions") Signed-off-by:Vinson Lee <vlee@freedesktop.org> Reviewed-by:
Jason Ekstrand <jason@jlekstrand.net> Part-of: <mesa/mesa!12290> (cherry picked from commit 8d679f4f)