moveFile on windows forgot to delete src file in fallback case

This dates back to commit 625303226d,
where a cross-device moveFile on Windows was made to fall back to copying
to the destination, but forgot to delete the source file.

Should fix the following test suite failure on Windows:

    import:                                FAIL (2.52s)
      .\Test\Framework.hs:383:
      C:\Users\RUNNER~1\AppData\Local\Temp\importtest.0\import1\f exists unexpectedly
      Use -p '/import/' to rerun this test only.

Which was seen here, running the test suite in the github action environment.
https://github.com/psychoinformatics-de/git-annex-wheel/issues/5

Utility/MoveFile.hs

@@ -65,10 +65,12 @@ moveFile src dest = tryIO (renamePath src dest) >>= onrename
 			let (ok, e') = case r of
 				Left err -> (False, err)
 				Right _ -> (True, e)
+			when ok $
+				void $ tryIO $ removeFile src
 #endif
 			unless ok $ do
 				-- delete any partial
-				_ <- tryIO $ removeFile tmp
+				void $ tryIO $ removeFile tmp
 				throwM e'
 
 #ifndef mingw32_HOST_OS