remove trailing whitespace

tests/run-make/c-link-to-rust-va-list-fn/rmake.rs

@@ -1,5 +1,5 @@
 // test.c and its static library checkrust.rs make use of variadic functions (VaList).
-// This test checks that the use of this feature does not 
+// This test checks that the use of this feature does not
 // prevent the creation of a functional binary.
 // See https://github.com/rust-lang/rust/pull/49878