tests/html-tests/copy.hs: Use mapM_ instead of mapM

So we do net get a list of () on stdout when running with runhaskell.

1 files changed, 3 insertions, 2 deletions

diff --git a/tests/html-tests/copy.hs b/tests/html-tests/copy.hs
index fe1e5422..188bfd33 100644
--- a/tests/html-tests/copy.hs
+++ b/tests/html-tests/copy.hs
@@ -7,15 +7,16 @@ import Data.List
 import Control.Monad
 
 
+main :: IO ()
 main = do
   args <- getArgs
   dir <- getCurrentDirectory
   contents <- getDirectoryContents (dir </> "output")
   if not $ null args
     then
-      mapM copy [ "output" </> file  | file <- contents, ".html" `isSuffixOf` file, takeBaseName file `elem` args  ]
+      mapM_ copy [ "output" </> file  | file <- contents, ".html" `isSuffixOf` file, takeBaseName file `elem` args  ]
     else
-      mapM copy [ "output" </> file | file <- contents, ".html" `isSuffixOf` file ]
+      mapM_ copy [ "output" </> file | file <- contents, ".html" `isSuffixOf` file ]
 
 
 copy file = do