block: Assert BlockDriver::format_name is not NULL

bdrv_do_find_format() calls strcmp() using BlockDriver::format_name
as argument, which must not be NULL. Assert this field is not null
when we register a block driver in bdrv_register().

Reported-by: Mansour Ahmadi <ManSoSec@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200318222235.23856-1-philmd@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
1 file changed