sort: allocate grn_obj as separated array and use them as pointer
sort: allocate grn_obj as separated array and use them as pointer

kenhys/groonga,naoa/groonga,naoa/groonga,komainu8/groonga,kenhys/groonga,groonga/groonga,naoa/groonga,naoa/groonga,groonga/groonga,groonga/groonga,kenhys/groonga,komainu8/groonga,kenhys/groonga,naoa/groonga,kenhys/groonga,komainu8/groonga,naoa/groonga,kenhys/groonga,groonga/groonga,komainu8/groonga,groonga/groonga,komainu8/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,komainu8/groonga,groonga/groonga,groonga/groonga,naoa/groonga,naoa/groonga,komainu8/groonga,komainu8/groonga