[libxml2] Fix xml2-config error code

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 2a357ab99e6f5c9196384b11cd91dd993f93014c
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Mon Nov 11 11:29:17 2019 +0100

    Fix xml2-config error code
    
    Return an error code if called with an unknown option.

 xml2-config.in | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/xml2-config.in b/xml2-config.in
index c25558c2..5863ffa0 100644
--- a/xml2-config.in
+++ b/xml2-config.in
@@ -97,8 +97,7 @@ while test $# -gt 0; do
         ;;
 
     *)
-       usage
-       exit 1
+       usage 1
        ;;
     esac
     shift