Fix dependency in BUILDING.md

btrfs/ioctl.h is now included in libbtrfs-dev instead of btrfs-tools.
Update BUILDING.md Dockerfile to install the correct dependency.

Resolves: #3813

Signed-off-by: Reid Li <reid.li@utexas.edu>
(cherry picked from commit a647407)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

BUILDING.md

@@ -135,7 +135,7 @@ You can build an image from this `Dockerfile`:
 FROM golang
 
 RUN apt-get update && \
-    apt-get install -y btrfs-tools libseccomp-dev
+    apt-get install -y libbtrfs-dev libseccomp-dev
 ```
 
 Let's suppose that you built an image called `containerd/build`. From the