Fix uninitiailzed variable in test

testsuite/expect/inc3.11.8

@@ -60,6 +60,7 @@ proc inc3_11_8 {} {
 	set thread_res_num [ expr $core_res_num * $res_thread_cnt ]
 
 	# (First test) Submit the batch job: a simple job using half the threads on the nodes
+	set job_id 0
 	set sbatch_pid [spawn $sbatch --nodes=1-$num_nodes --time=10:00 --ntasks-per-node=$thread_res_num --output=/dev/null $file_in]
 	expect {
 		-re "Submitted batch job ($number)" {