fixup! async generator using roslyn compiler

Author: hazzik

src/NHibernate/Engine/IBatcher.cs

@@ -119,7 +119,7 @@ public partial interface IBatcher : IDisposable
 		/// The Batcher is responsible for ensuring that all of the Drivers rules for how many open
 		/// <see cref="DbDataReader"/>s it can have are followed.
 		/// </remarks>
-		DbDataReader ExecuteReader(IDbCommand cmd);
+		DbDataReader ExecuteReader(DbCommand cmd);
 
 		/// <summary>
 		/// Executes the <see cref="DbCommand"/>.