hack: Remove inContainer check, it wasn't useful

The inContainer check isn't really useful anymore.

Even though it was said that we shouldn't rely on its existence back in
2016, we're now in 2019 and this thing still exists so we should just
rely on it now to check whether or not we're in a container.

Signed-off-by: Eli Uriegas <eli.uriegas@docker.com>

hack/make.sh

@@ -28,30 +28,6 @@ export SCRIPTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 export MAKEDIR="$SCRIPTDIR/make"
 export PKG_CONFIG=${PKG_CONFIG:-pkg-config}
 
-# We're a nice, sexy, little shell script, and people might try to run us;
-# but really, they shouldn't. We want to be in a container!
-inContainer="AssumeSoInitially"
-if [ "$(go env GOHOSTOS)" = 'windows' ]; then
-	if [ -z "$FROM_DOCKERFILE" ]; then
-		unset inContainer
-	fi
-else
-	if [ "$PWD" != "/go/src/$DOCKER_PKG" ]; then
-		unset inContainer
-	fi
-fi
-
-if [ -z "$inContainer" ]; then
-	{
-		echo "# WARNING! I don't seem to be running in a Docker container."
-		echo "# The result of this command might be an incorrect build, and will not be"
-		echo "# officially supported."
-		echo "#"
-		echo "# Try this instead: make all"
-		echo "#"
-	} >&2
-fi
-
 echo
 
 # List of bundles to create when no argument is passed