Clarify getting started instructions for git checkouts

The default branch is already devel (as of June 14, 2012), so there's
no need to check this one out explicitly.  Also, it was being checked
out before we had even entered the source folder, which was obviously
a mistake.

rst/gettingstarted.rst

@@ -56,7 +56,6 @@ Ansible is trivially easy to run from a checkout, root permissions are not requi
 to use it::
 
     $ git clone git://github.com/ansible/ansible.git
-    $ git checkout -t origin/devel
     $ cd ./ansible
     $ source ./hacking/env-setup
 
@@ -77,7 +76,6 @@ If you are not working from a distribution where Ansible is packaged yet, you ca
 using "make install".  This is done through `python-distutils`::
 
     $ git clone git://github.com/ansible/ansible.git
-    $ git checkout -t origin/devel
     $ cd ./ansible
     $ sudo make install