To prevent infinite recursion when grub_mm_debug is on, disable it when
calling grub_vprintf(). One such call loop is:
grub_vprintf() -> parse_printf_args() -> parse_printf_arg_fmt() ->
grub_debug_calloc() -> grub_printf() -> grub_vprintf().
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>