Don't need to init testr explicitly

In run_tests.sh, function init_testr will initialize testr if the
directory .testrepository is not existed. Actually, testr will do
the check before run the test:

In Python package testrepository, setuptools_command.py:Testr.run

68 def run(self):
69     """Set up testr repo, then run testr"""
70     if not os.path.isdir(".testrepository"):
71         self._run_testr("init")

So, init_testr can be removed safely.

Fixes Bug #1216820
Change-Id: Id9815033c0cb0e1aa6693a4c14bf9a5d490c8883

run_tests.sh

@@ -109,12 +109,6 @@ if [ $no_site_packages -eq 1 ]; then
   installvenvopts="--no-site-packages"
 fi
 
-function init_testr {
-  if [ ! -d .testrepository ]; then
-    ${wrapper} testr init
-  fi
-}
-
 function run_tests {
   # Cleanup *pyc
   ${wrapper} find . -type f -name "*.pyc" -delete
@@ -235,7 +229,6 @@ if [ $recreate_db -eq 1 ]; then
     rm -f tests.sqlite
 fi
 
-init_testr
 run_tests
 
 # NOTE(sirp): we only want to run pep8 when we're running the full-test suite,