Fix test runner run_tests.sh is broken

run_tests.sh contains incorrect variable assignment at line 80
which makes script to fail when trying to run tests.

Fixes: bug #1105000

Change-Id: Ib29c50f28d8b7e09935cd4136e709e0e0141ad2a

Author: Ilya Persky

run_tests.sh

@@ -77,7 +77,7 @@ function run_tests {
   if [ $coverage -eq 1 ]; then
     # Do not test test_coverage_ext when gathering coverage.
     if [ "x$testrargs" = "x" ]; then
-      testrargs = "^(?!.*test_coverage_ext).*$"
+      testrargs="^(?!.*test_coverage_ext).*$"
     fi
     export PYTHON="${wrapper} coverage run --source novaclient --parallel-mode"
   fi