Fix a style complaint

snoyberg · borsboom · commit 5cd02c166fe3 · 2016-12-01T15:17:15.000-08:00
diff --git a/src/Stack/Upgrade.hs b/src/Stack/Upgrade.hs
@@ -173,7 +173,7 @@ binaryUpgrade (BinaryOpts mplatform force' mver morg mrepo) = do
             ec <- rawSystem (toFilePath tmpFile) ["--version"]
 
             unless (ec == ExitSuccess)
-                    $ error $ "Non-success exit code from running newly downloaded executable"
+                    $ error "Non-success exit code from running newly downloaded executable"
 
 sourceUpgrade
   :: (StackM env m, HasConfig env)
