pkgfuncs.inc.php: Fix undefined variable notice

Fixes a undefined variable notice in getvotes() that popped up when a
package without any votes was requested.
Signed-off-by: Lukas Fleischer <archlinux@cryptocrack.de>

web/lib/pkgfuncs.inc.php

@@ -993,6 +993,7 @@ function getvotes($pkgid, $dbh=NULL) {
 		return;
 	}
 
+	$votes = array();
 	while ($row = $result->fetch(PDO::FETCH_ASSOC)) {
 		$votes[] = $row;
 	}