auth_gssapi - fix test result and let the test run on Windows buildbot

mysql-test/collections/buildbot_suites.bat

@@ -4,4 +4,5 @@ innodb,^
 plugins,^
 mariabackup,^
 roles,^
+auth_gssapi,^
 rocksdb

plugin/auth_gssapi/mysql-test/auth_gssapi/basic.result

 INSTALL SONAME 'auth_gssapi';
+Warnings:
+Note	1105	SSPI: using principal name 'localhost', mech 'Negotiate'
 CREATE USER 'GSSAPI_SHORTNAME' IDENTIFIED WITH gssapi;
+connect  con1,localhost,$GSSAPI_SHORTNAME,,;
 SELECT USER(),CURRENT_USER();
 USER()	CURRENT_USER()
 GSSAPI_SHORTNAME@localhost	GSSAPI_SHORTNAME@%
+disconnect con1;
+connection default;
 DROP USER 'GSSAPI_SHORTNAME';
 CREATE USER nosuchuser IDENTIFIED WITH gssapi;
 ERROR 28000: GSSAPI name mismatch, requested 'nosuchuser', actual name 'GSSAPI_SHORTNAME'
 DROP USER nosuchuser;
 CREATE USER usr1 IDENTIFIED WITH gssapi as 'GSSAPI_FULLNAME';
+connect  con1,localhost,usr1,,;
 SELECT USER(),CURRENT_USER();
 USER()	CURRENT_USER()
 usr1@localhost	usr1@%
+disconnect con1;
+connection default;
 DROP USER usr1;
 CREATE USER nosuchuser IDENTIFIED WITH gssapi AS 'nosuchuser@EXAMPLE.COM';
 ERROR 28000: GSSAPI name mismatch, requested 'nosuchuser@EXAMPLE.COM', actual name 'GSSAPI_FULLNAME'

plugin/auth_gssapi/sspi_server.cc

@@ -284,7 +284,7 @@ int plugin_init()
   {
     srv_principal_name= get_default_principal_name();
   }
-  my_printf_error(0, "SSPI: using principal name '%s', mech '%s'",
+  my_printf_error(ER_UNKNOWN_ERROR, "SSPI: using principal name '%s', mech '%s'",
                   ME_ERROR_LOG | ME_NOTE, srv_principal_name, srv_mech_name);
 
   ret = AcquireCredentialsHandle(