YARN-8518. test-container-executor test_is_empty() is broken (Jim_Brennan via rkanter)

(cherry picked from commit 1bc106a)
(cherry picked from commit 6e0db6f)
(cherry picked from commit edb9d8b)
(cherry picked from commit d9b9c91)

Author: rkanter

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/test/test-container-executor.c

@@ -995,19 +995,23 @@ void test_get_docker_binary() {
   free(docker_binary_user);
 }
 
+int is_empty(char *name);
+
 void test_is_empty() {
   printf("\nTesting is_empty function\n");
   if (is_empty("/")) {
     printf("FAIL: / should not be empty\n");
     exit(1);
   }
-  if (is_empty("/tmp/2938rf2983hcqnw8ud/noexist")) {
-    printf("FAIL: /tmp/2938rf2983hcqnw8ud/noexist should not exist\n");
+  char *noexist = TEST_ROOT "/noexist";
+  if (is_empty(noexist)) {
+    printf("%s should not exist\n", noexist);
     exit(1);
   }
-  mkdir("/tmp/2938rf2983hcqnw8ud/emptydir", S_IRWXU);
-  if (!is_empty("/tmp/2938rf2983hcqnw8ud/emptydir")) {
-    printf("FAIL: /tmp/2938rf2983hcqnw8ud/emptydir be empty\n");
+  char *emptydir = TEST_ROOT "/emptydir";
+  mkdir(emptydir, S_IRWXU);
+  if (!is_empty(emptydir)) {
+    printf("FAIL: %s should be empty\n", emptydir);
     exit(1);
   }
 }