[dev_setup][bugfix] Untar from cache

This fixes a bug in I575c76ff , I3bd5e089 and Id1b8e362 that tried
decompressing the source tarballs from /tmp instead of the cache
location.

  Test plan: run dev_setup with no cached tarball and no built rubies,
node.js or erlang.

Change-Id: I97d0595bdf3e1f85335a5e8841e28433028219f9

dev_setup/cookbooks/erlang/recipes/default.rb

@@ -8,7 +8,8 @@
   package pkg
 end
 
-remote_file File.join(node[:deployment][:setup_cache], "otp_src_#{node[:erlang][:version]}.tar.gz") do
+tarball_path = File.join(node[:deployment][:setup_cache], "otp_src_#{node[:erlang][:version]}.tar.gz")
+remote_file tarball_path do
   owner node[:deployment][:user]
   source node[:erlang][:source]
   checksum "849d050b59821e9f2831fee2e3267d84b410eee860a55f6fc9320cc00b5205bd"
@@ -26,7 +27,7 @@ bash "Install Erlang" do
   cwd File.join("", "tmp")
   user node[:deployment][:user]
   code <<-EOH
-  tar xvzf otp_src_#{node[:erlang][:version]}.tar.gz
+  tar xvzf #{tarball_path}
   cd otp_src_#{node[:erlang][:version]}
   #{File.join(".", "configure")} --prefix=#{node[:erlang][:path]} --disable-hipe
   make

dev_setup/cookbooks/node/libraries/nodejs_install.rb

@@ -4,7 +4,8 @@ module NodeInstall
       package pkg
     end
 
-    remote_file File.join(node[:deployment][:setup_cache], "node-v#{node_version}.tar.gz") do
+    tarball_path = File.join(node[:deployment][:setup_cache], "node-v#{node_version}.tar.gz")
+    remote_file tarball_path do
       owner node[:deployment][:user]
       source node_source
       checksum node[:node][:checksums][node_version]
@@ -22,7 +23,7 @@ module NodeInstall
       cwd File.join("", "tmp")
       user node[:deployment][:user]
       code <<-EOH
-      tar xzf node-v#{node_version}.tar.gz
+      tar xzf #{tarball_path}
       cd node-v#{node_version}
       ./configure --prefix=#{node_path}
       make

dev_setup/cookbooks/ruby/libraries/ruby_install.rb

@@ -8,7 +8,8 @@ module RubyInstall
       package pkg
     end
 
-    remote_file File.join(node[:deployment][:setup_cache], "ruby-#{ruby_version}.tar.gz") do
+    tarball_path = File.join(node[:deployment][:setup_cache], "ruby-#{ruby_version}.tar.gz")
+    remote_file tarball_path do
       owner node[:deployment][:user]
       source ruby_source
       checksum node[:ruby][:checksums][ruby_version]
@@ -26,7 +27,7 @@ module RubyInstall
       cwd File.join("", "tmp")
       user node[:deployment][:user]
       code <<-EOH
-      tar xzf ruby-#{ruby_version}.tar.gz
+      tar xzf #{tarball_path}
       cd ruby-#{ruby_version}
       ./configure --disable-pthread --prefix=#{ruby_path}
       make