Don't expose free pointer.

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@21134 ec53bebd-3082-4978-b11e-865c3cabbd6b

lib/krb5/plugin.c

@@ -96,6 +96,7 @@ loadlib(krb5_context context,
     (*e)->dsohandle = dlopen(lib, RTLD_LAZY);
     if ((*e)->dsohandle == NULL) {
 	free(*e);
+	*e = NULL;
 	krb5_set_error_string(context, "Failed to load %s: %s", 
 			      lib, dlerror());
 	return ENOMEM;