MDEV-23358 main.upgrade_MDEV-19650 fails with result difference

When including a generated file, always use <...>.
We need the compiler to find it in the BINDIR, not in the SRCDIR.
But when including as "..." SRCDIR is always searched first.

The bug can only happen in out-of-source builds, if there was an
in-source build before.

client/mysql_upgrade.c

@@ -18,7 +18,7 @@
 
 #include "client_priv.h"
 #include <sslopt-vars.h>
-#include "../scripts/mysql_fix_privilege_tables_sql.c"
+#include <../scripts/mysql_fix_privilege_tables_sql.c>
 
 #include <welcome_copyright_notice.h> /* ORACLE_WELCOME_COPYRIGHT_NOTICE */