filestore: Correct Coverity RESOURCE_LEAK issue

This commit corrects the RESOURCE_LEAK issue (CID 1465222) of the `FILE`
pointer.

src/output-filestore.c

@@ -177,6 +177,7 @@ static void OutputFilestoreFinalizeFiles(ThreadVars *tv,
                 if (out != NULL) {
                     size_t js_len = jb_len(js_fileinfo);
                     fwrite(jb_ptr(js_fileinfo), js_len, 1, out);
+                    fclose(out);
                 }
                 jb_free(js_fileinfo);
             }