vcs-svn: drop no-op reset methods

Since v1.7.5~42^2~6 (vcs-svn: remove buffer_read_string)
buffer_reset() does nothing thus fast_export_reset() also.

Signed-off-by: David Barr <davidbarr@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

test-svn-fe.c

@@ -31,9 +31,7 @@ static int apply_delta(int argc, char *argv[])
 		die_errno("cannot close preimage");
 	if (buffer_deinit(&delta))
 		die_errno("cannot close delta");
-	buffer_reset(&preimage);
 	strbuf_release(&preimage_view.buf);
-	buffer_reset(&delta);
 	return 0;
 }