fix typo in c_simple_example

Summary: fix typo

Test Plan: none

Reviewers: tfarina, igor

Reviewed By: tfarina, igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D37347

examples/c_simple_example.c

@@ -27,7 +27,7 @@ int main(int argc, char **argv) {
   db = rocksdb_open(options, DBPath, &err);
   assert(!err);
 
-  // open Backup Engine that we will use for backing up or database
+  // open Backup Engine that we will use for backing up our database
   be = rocksdb_backup_engine_open(options, DBBackupPath, &err);
   assert(!err);