[TEST][SPARKR][CORE] Fix broken SparkSubmitSuite

## What changes were proposed in this pull request?

Fix test file path. This is broken in #18264 and undetected since R-only changes don't build core and subsequent post-commit with the change built fine (again because it wasn't building core)

actually appveyor builds everything but it's not running scala suites ...

## How was this patch tested?

jenkins
srowen gatorsmile

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #18283 from felixcheung/rsubmitsuite.