cryptodev: fix memory leak during stats query

cryptodev: fix memory leak during stats query

object_get_canonical_path already returns newly allocated memory, this
means no additional g_strdup required. Remove g_strdup to avoid memory
leak.

Fixes: Coverity CID 1508074
Fixes: f2b901098 ("cryptodev: Support query-stats QMP command")
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230503115437.262469-1-pizhenwei@bytedance.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>