block/file-posix: Extract raw_regular_truncate()

This functionality is part of raw_create() which we will be able to
reuse nicely in raw_truncate().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20170613202107.10125-7-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
1 file changed