Don't need to init testr in run_tests.sh

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 #1222688
Change-Id: I51e73efe4e9b80bbf0159a5bce0db81fc049b9ce

tools/run_tests_common.sh

@@ -101,11 +101,6 @@ export VENV_NAME
 export WITH_VENV
 export VENV=${VENV_PATH}/${VENV_DIR}
 
-function init_testr {
-  if [ ! -d .testrepository ]; then
-    ${WRAPPER} testr init
-  fi
-}
 
 function run_tests {
   # Cleanup *pyc
@@ -239,7 +234,6 @@ 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,