i915/gem/selftests: Assign the VM at context creation in igt_shared_ctx_exec

We want to delete __assign_ppgtt and, generally, stop setting the VM
after context creation.  This is the one place I could find in the
selftests where we set a VM after the fact.
Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210708154835.528166-29-jason@jlekstrand.net

drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c

@@ -813,16 +813,12 @@ static int igt_shared_ctx_exec(void *arg)
 			struct i915_gem_context *ctx;
 			struct intel_context *ce;
 
-			ctx = kernel_context(i915, NULL);
+			ctx = kernel_context(i915, ctx_vm(parent));
 			if (IS_ERR(ctx)) {
 				err = PTR_ERR(ctx);
 				goto out_test;
 			}
 
-			mutex_lock(&ctx->mutex);
-			__assign_ppgtt(ctx, ctx_vm(parent));
-			mutex_unlock(&ctx->mutex);
-
 			ce = i915_gem_context_get_engine(ctx, engine->legacy_idx);
 			GEM_BUG_ON(IS_ERR(ce));