Free I/O buffers when we are finished with them!

src/core/posix_io.c

 	struct io_buffer *tmp;
 
 	list_for_each_entry_safe ( iobuf, tmp, &file->data, list ) {
+		list_del ( &iobuf->list );
 		free_iob ( iobuf );
 	}
 	free ( file );
 			copy_to_user ( buffer, offset, iobuf->data,
 				       frag_len );
 			iob_pull ( iobuf, frag_len );
-			if ( ! iob_len ( iobuf ) )
+			if ( ! iob_len ( iobuf ) ) {
+				list_del ( &iobuf-> list );
 				free_iob ( iobuf );
+			}
 			file->pos += frag_len;
 			len += frag_len;
 			offset += frag_len;