[libxml2] Remove duplicated code in xmlcatalog

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 91b3d3f95ba5cbafe619336c468916f950efa407
Author: David King <amigadave amigadave com>
Date:   Wed Jul 14 17:12:11 2021 +0100

    Remove duplicated code in xmlcatalog
    
    Found by Coverity.
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1938806

 xmlcatalog.c | 35 ++++++++++-------------------------
 1 file changed, 10 insertions(+), 25 deletions(-)
---
diff --git a/xmlcatalog.c b/xmlcatalog.c
index 3f0e1b9c..7b6f3769 100644
--- a/xmlcatalog.c
+++ b/xmlcatalog.c
@@ -214,32 +214,17 @@ static void usershell(void) {
                }
            }
        } else if (!strcmp(command, "add")) {
-           if (sgml) {
-               if ((nbargs != 3) && (nbargs != 2)) {
-                   printf("add requires 2 or 3 arguments\n");
-               } else {
-                   if (argv[2] == NULL)
-                       ret = xmlCatalogAdd(BAD_CAST argv[0], NULL,
-                                           BAD_CAST argv[1]);
-                   else
-                       ret = xmlCatalogAdd(BAD_CAST argv[0], BAD_CAST argv[1],
-                                           BAD_CAST argv[2]);
-                   if (ret != 0)
-                       printf("add command failed\n");
-               }
+           if ((nbargs != 3) && (nbargs != 2)) {
+               printf("add requires 2 or 3 arguments\n");
            } else {
-               if ((nbargs != 3) && (nbargs != 2)) {
-                   printf("add requires 2 or 3 arguments\n");
-               } else {
-                   if (argv[2] == NULL)
-                       ret = xmlCatalogAdd(BAD_CAST argv[0], NULL,
-                                           BAD_CAST argv[1]);
-                   else
-                       ret = xmlCatalogAdd(BAD_CAST argv[0], BAD_CAST argv[1],
-                                           BAD_CAST argv[2]);
-                   if (ret != 0)
-                       printf("add command failed\n");
-               }
+               if (argv[2] == NULL)
+               ret = xmlCatalogAdd(BAD_CAST argv[0], NULL,
+                                   BAD_CAST argv[1]);
+               else
+                   ret = xmlCatalogAdd(BAD_CAST argv[0], BAD_CAST argv[1],
+                                       BAD_CAST argv[2]);
+               if (ret != 0)
+                   printf("add command failed\n");
            }
        } else if (!strcmp(command, "del")) {
            if (nbargs != 1) {