Fix in scheme backend and test script

At least on Linux, \r needs to be in singles quotes as an argument to tr
or it removes all the 'r' instead! Hopefully it also works this way on
Windows...

src/Compiler/Scheme/Chez.idr

@@ -49,7 +49,7 @@ escapeQuotes s = pack $ foldr escape [] $ unpack s
 
 schHeader : String -> List String -> String
 schHeader chez libs
-  = if os /= "windows" then "#!" ++ chez ++ " --script\n\n" else "" ++
+  = (if os /= "windows" then "#!" ++ chez ++ " --script\n\n" else "") ++
     "(import (chezscheme))\n" ++
     "(case (machine-type)\n" ++
     "  [(i3le ti3le a6le ta6le) (load-shared-object \"libc.so.6\")]\n" ++

tests/Main.idr

@@ -70,7 +70,7 @@ runTest : String -> String -> String -> IO Bool
 runTest dir prog test
     = do chdir (dir ++ "/" ++ test)
          putStr $ dir ++ "/" ++ test ++ ": "
-         system $ "sh ./run " ++ prog ++ " | tr -d \\r > output"
+         system $ "sh ./run " ++ prog ++ " | tr -d '\\r' > output"
          Right out <- readFile "output"
                | Left err => do print err
                                 pure False