[Rally] Fix job for Manila project

Rally CI job config for Manila project is obsolete and not
compatible with Manila hooks anymore. Right now it expects
three params be provided for "pre_test_hook.sh" but only one
is provided. It leads to improper job configuration and errors.

Therefore, provide lost params explicitly.

Change-Id: Icfa6a12b159561f89bb4f5f4680aa3ed5ed93077

jenkins/jobs/rally.yaml

@@ -208,7 +208,9 @@
           function pre_test_hook {{
               # Install manila-devstack integration
               # 'dhss' means 'drivers handle share servers'
-              source $BASE/new/manila/contrib/ci/pre_test_hook.sh {dhss}
+              # 'driver' is codename of shar driver in manila
+              # that is used for proper configuration of storage backend.
+              source $BASE/new/manila/contrib/ci/pre_test_hook.sh {dhss} {driver} 'multibackend'
           }}
           export -f pre_test_hook
 
@@ -236,6 +238,7 @@
       - devstack-manila-rally-gate-multibackend:
           scenario: 'rally-manila'
           dhss: '1'
+          driver: 'generic'
 
     publishers:
       - devstack-logs
@@ -256,6 +259,7 @@
       - devstack-manila-rally-gate-multibackend:
           scenario: 'rally-manila-no-ss'
           dhss: '0'
+          driver: 'zfsonlinux'
 
     publishers:
       - devstack-logs