Change test directive from check-pass to run-pass

Update test to check for run-pass instead of check-pass.

Author: DrAsu33

tests/ui/issues/issue-zst-nthback-148682.rs

@@ -1,5 +1,4 @@
-// @ check-pass
-//test Intolter::nth_back does not cause UB for ZSTs with high alignment
+//@ run-pass
 #[repr(align(8))]
 struct Thing;