Revert "avutil/hwcontext_vaapi: fix SEGV in vaTerminate when vaInitialize fails"

The original code is correctly following the API - vaTerminate() must
be called to free the resources of a VADisplay after it is created by
any of the vaGetDisplay*() calls; it is not necessary to have
successfully called vaInitialize() on it.  The segfaults which
prompted this change must therefore be bugs in libva or the driver it
loads.

This reverts commit 3606602f.

libavutil/hwcontext_vaapi.c

@@ -961,13 +961,14 @@ static int vaapi_device_create(AVHWDeviceContext *ctx, const char *device,
         return AVERROR(EINVAL);
     }
 
+    hwctx->display = display;
+
     vas = vaInitialize(display, &major, &minor);
     if (vas != VA_STATUS_SUCCESS) {
         av_log(ctx, AV_LOG_ERROR, "Failed to initialise VAAPI "
                "connection: %d (%s).\n", vas, vaErrorStr(vas));
         return AVERROR(EIO);
     }
-    hwctx->display = display;
     av_log(ctx, AV_LOG_VERBOSE, "Initialised VAAPI connection: "
            "version %d.%d\n", major, minor);