Fix quotes in exception messages

Author: fabpot

Filesystem.php

@@ -388,10 +388,10 @@ private function linkException($origin, $target, $linkType)
     {
         if (self::$lastError) {
             if ('\\' === \DIRECTORY_SEPARATOR && false !== strpos(self::$lastError, 'error code(1314)')) {
-                throw new IOException(sprintf('Unable to create %s link due to error code 1314: \'A required privilege is not held by the client\'. Do you have the required Administrator-rights?', $linkType), 0, null, $target);
+                throw new IOException(sprintf('Unable to create "%s" link due to error code 1314: \'A required privilege is not held by the client\'. Do you have the required Administrator-rights?', $linkType), 0, null, $target);
             }
         }
-        throw new IOException(sprintf('Failed to create %s link from "%s" to "%s".', $linkType, $origin, $target), 0, null, $target);
+        throw new IOException(sprintf('Failed to create "%s" link from "%s" to "%s".', $linkType, $origin, $target), 0, null, $target);
     }
 
     /**