Revert "docker: Lock image build"

This reverts commit f2066af.

Author: madadam

docker/linux.sh

@@ -139,14 +139,8 @@ function print_help() {
 function build_container() {
     log_group_begin "Building image $image_name"
 
-    local ndk_version=$(cat ndk-version.txt)
-
-    flock --exclusive docker/Dockerfile.linux \
-        docker $(docker_host) build \
-            --tag $image_name \
-            --file docker/Dockerfile.linux \
-            --build-arg NDK_VERSION=$ndk_version \
-            docker
+    ndk_version=$(cat ndk-version.txt)
+    dock build -t $image_name --build-arg NDK_VERSION=$ndk_version - < docker/Dockerfile.linux
 
     log_group_end
 }

docker/utils.sh

@@ -24,16 +24,14 @@ function check_dependency {
     command -v $dep >/dev/null 2>&1 || { error "'$dep' is not installed"; }
 }
 
-function docker_host() {
+function dock() {
     if [ -n "$host" ]; then
-        echo -n "--host ssh://$host"
+        docker --host ssh://$host "$@"
+    else
+        docker "$@"
     fi
 }
 
-function dock() {
-    docker $(docker_host) "$@"
-}
-
 function exe() (
     local opts=
     local history_log=