in quota wrapper use === instead of ! for better readability and as in other wrappers

lib/private/files/stream/quota.php

@@ -83,7 +83,7 @@ class Quota {
 		}
 		// this wrapper needs to return "true" for success.
 		// the fseek call itself returns 0 on succeess
-		return !fseek($this->source, $offset, $whence);
+		return fseek($this->source, $offset, $whence) === 0;
 	}
 
 	public function stream_tell() {