Fix valgrind error in c_test

Summary:
External contribution caused some valgrind errors: 1a34aaaef0

This diff fixes them

Test Plan: ran valgrind

Reviewers: sdong, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19485

db/c.cc

@@ -507,6 +507,13 @@ char** rocksdb_list_column_families(
   return column_families;
 }
 
+void rocksdb_list_column_families_destroy(char** list, size_t len) {
+  for (size_t i = 0; i < len; ++i) {
+    free(output[i]);
+  }
+  free(output);
+}
+
 rocksdb_column_family_handle_t* rocksdb_create_column_family(
     rocksdb_t* db,
     const rocksdb_options_t* column_family_options,

db/c_test.c

@@ -580,6 +580,7 @@ int main(int argc, char** argv) {
     CheckEqual("default", column_fams[0], 7);
     CheckEqual("cf1", column_fams[1], 3);
     CheckCondition(cflen == 2);
+    rocksdb_list_column_families_destroy(column_fams, cflen);
 
     rocksdb_options_t* cf_options = rocksdb_options_create();
 
@@ -631,14 +632,15 @@ int main(int argc, char** argv) {
     for (i = 0; i < 2; i++) {
       rocksdb_column_family_handle_destroy(handles[i]);
     }
+    rocksdb_close(db);
+    rocksdb_destroy_db(options, dbname, &err);
+    rocksdb_options_destroy(db_options);
+    rocksdb_options_destroy(cf_options);
   }
 
   StartPhase("prefix");
   {
     // Create new database
-    rocksdb_close(db);
-    rocksdb_destroy_db(options, dbname, &err);
-
     rocksdb_filterpolicy_t* policy = rocksdb_filterpolicy_create_bloom(10);
     rocksdb_options_set_filter_policy(options, policy);
     rocksdb_options_set_prefix_extractor(options, rocksdb_slicetransform_create_fixed_prefix(3));

include/rocksdb/c.h

@@ -119,6 +119,7 @@ char** rocksdb_list_column_families(
     const char* name,
     size_t* lencf,
     char** errptr);
+void rocksdb_list_column_families_destroy(char** list, size_t len);
 
 extern rocksdb_column_family_handle_t* rocksdb_create_column_family(
     rocksdb_t* db,