tests: Trim .nim files trailing whitespace

via OSX: find . -name '*.nim' -exec sed -i '' -E 's/[[:space:]]+$//' {} +

tests/macros/tprintf.nim

@@ -2,15 +2,15 @@ discard """
   file: "tprintf.nim"
   output: "Andreas Rumpf"
 """
-# Test a printf proc
-
-proc printf(file: TFile, args: openarray[string]) =
-  var i = 0
-  while i < args.len:
-    write(file, args[i])
-    inc(i)
-
-printf(stdout, ["Andreas ", "Rumpf\n"])
-#OUT Andreas Rumpf
+# Test a printf proc
+
+proc printf(file: TFile, args: openarray[string]) =
+  var i = 0
+  while i < args.len:
+    write(file, args[i])
+    inc(i)
+
+printf(stdout, ["Andreas ", "Rumpf\n"])
+#OUT Andreas Rumpf