testing/fstest: add cleanup to fatutf8

Signed-off-by: fanzhuyun <fanzhuyun@xiaomi.com>

testing/fatutf8/fatutf8_main.c

@@ -60,7 +60,7 @@ int main(int argc, FAR char *argv[])
   int len;
 
   char buf[128];
-  char path[256];
+  char path[PATH_MAX];
 
   char *basepath = NULL;
 
@@ -166,5 +166,33 @@ int main(int argc, FAR char *argv[])
       exit(fd);
     }
 
+  printf("\n");
+
+  ret = remove(path);
+  if (ret == 0)
+    {
+      printf("removed %s\n", path);
+      basepath = strrchr(path, '/');
+      if (basepath != NULL)
+        {
+          *basepath = '\0';
+          ret = remove(path);
+          if (ret == 0)
+            {
+              printf("removed %s\n", path);
+            }
+          else
+            {
+              printf("remove failed: %d\n", errno);
+              exit(ret);
+            }
+        }
+    }
+  else
+    {
+      printf("remove failed: %d\n", errno);
+      exit(ret);
+    }
+
   return EXIT_SUCCESS;
 }