Dockerfile.simple: Fix compile docker binary error with btrfs
Use the image build from Dockerfile.simple to build docker binary failed
with not find <brtfs/ioctl.h>, we need to install libbtrfs-dev to fix this.
```
Building: bundles/dynbinary-daemon/dockerd-dev
GOOS="" GOARCH="" GOARM=""
.gopath/src/github.com/docker/docker/daemon/graphdriver/btrfs/btrfs.go:8:10: fatal error: btrfs/ioctl.h: No such file or directory
#include <btrfs/ioctl.h>
```
Signed-off-by: Lei Jitang <leijitang@outlook.com>
(cherry picked from commit dd7ee8ea3e9383b525780b4e624bc16ddbf4a70d)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>