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>

Dockerfile.simple

@@ -18,13 +18,13 @@ RUN sed -ri "s/(httpredir|deb).debian.org/$APT_MIRROR/g" /etc/apt/sources.list
 # https://github.com/docker/docker/blob/master/project/PACKAGERS.md#build-dependencies
 # https://github.com/docker/docker/blob/master/project/PACKAGERS.md#runtime-dependencies
 RUN apt-get update && apt-get install -y --no-install-recommends \
-		btrfs-tools \
 		build-essential \
 		curl \
 		cmake \
 		gcc \
 		git \
 		libapparmor-dev \
+		libbtrfs-dev \
 		libdevmapper-dev \
 		libseccomp-dev \
 		ca-certificates \