Testsuite - do not run test35.3 as root.

Burst buffer jobs cannot be run as root currently, change
test to prevent that.

Bug 3723.

testsuite/expect/test35.3

@@ -43,6 +43,8 @@ set output_use  "test$test_id-%A_%a.output"
 set script_use  "test$test_id.use.bash"
 set tmp_file    "test$test_id"
 
+stop_root_user
+
 proc find_bb_jobid { fname bb_jobid } {
 	global bin_cat