Don't change directory while running init-runonce

Currently init-runonce script changes directory to the
script's base directory (/usr/...) before doing anything else.
This unnecessarily _forces_ a non-root user to use sudo for
running this script thereby raising privileges for code which
doesn't want it. Also downloading temporary stuff in places like
/usr... seems not a good choice.

Hence deleting the said code part and letting the deployer work
comfortably from any directory.

Made documentation changes accordingly.

Change-Id: Ib3c7ed97aa5f53c115b6337aaf572b5fdc7a71f3
Closes-Bug: #1732963

doc/source/user/quickstart.rst

@@ -681,12 +681,10 @@ with a glance image and neutron networks.
     . /etc/kolla/admin-openrc.sh
 
     #centOS
-    cd /usr/share/kolla-ansible
-    ./init-runonce
+    /usr/share/kolla-ansible/init-runonce
 
     #ubuntu
-    cd /usr/local/share/kolla-ansible
-    ./init-runonce
+    /usr/local/share/kolla-ansible/init-runonce
 
 .. note::
 

tools/init-runonce

@@ -29,9 +29,6 @@ for i in curl openstack; do
         exit
     fi
 done
-# Move to top level directory
-REAL_PATH=$(python -c "import os,sys;print os.path.realpath('$0')")
-cd "$(dirname "$REAL_PATH")/.."
 
 # Test for credentials set
 if [[ "${OS_USERNAME}" == "" ]]; then