Remove lib/tempest errexit handling

lib/tempest had code to set -o errexit and restore the setting after
configure_tempest had run. This code didn't work, but it is no longer
necessary since we set errexit for all of devstack (see change 88521;
Change-Id Ia477e04567046a7fcdedf699423165bc577b72ad).

This changeset removes the errexit handling code from lib/tempest.

Change-Id: I2b0bc3c55a5d9bbb688f1e2e8e0fe133830a4172
diff --git a/lib/tempest b/lib/tempest
index 81eeba3..2125f88 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -76,7 +76,6 @@
     local num_images
     local image_uuid
     local image_uuid_alt
-    local errexit
     local password
     local line
     local flavors
@@ -92,11 +91,6 @@
     # TODO(afazekas):
     # sudo python setup.py deploy
 
-    # This function exits on an error so that errors don't compound and you see
-    # only the first error that occurred.
-    errexit=$(set +o | grep errexit)
-    set -o errexit
-
     # Save IFS
     ifs=$IFS
 
@@ -383,8 +377,6 @@
 
     # Restore IFS
     IFS=$ifs
-    #Restore errexit
-    $errexit
 }
 
 # create_tempest_accounts() - Set up common required tempest accounts