Correct key pointer usage in bdb_idl_fetch_key.

Author: Shogo Matsumoto
Resolves: #1356165

diff --git a/servers/slapd/back-bdb/idl.c b/servers/slapd/back-bdb/idl.c
--- a/servers/slapd/back-bdb/idl.c
+++ b/servers/slapd/back-bdb/idl.c
@@ -628,7 +628,7 @@ bdb_idl_fetch_key(
 					BDB_DISK2ID( j, i );
 				}
 			}
-			rc = cursor->c_get( cursor, key, &data, flags | DB_NEXT_DUP );
+			rc = cursor->c_get( cursor, kptr, &data, flags | DB_NEXT_DUP );
 		}
 		if ( rc == DB_NOTFOUND ) rc = 0;
 		ids[0] = i - ids;