gve: Do not fully free QPL pages on prefill errors

The prefill function should have only removed the page count bias it
added. Fully freeing the page will cause gve_free_queue_page_list to
free a page the driver no longer owns.

Fixes: 82fd151d

 ("gve: Reduce alloc and copy costs in the GQ rx path")
Signed-off-by: Shailend Chand <shailend@google.com>
Link: https://lore.kernel.org/r/20231014014121.2843922-1-shailend@google.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>