Tr: Re-fix plurals

The number for the plural must be given as the 3rd argument
to the tr() call, not as an arg().

Amends 1359e9c84f

Change-Id: I45241a6acd82041c320bbe476cd2b4cc92247ef3
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/libs/utils/devicefileaccess.cpp

@@ -721,10 +721,11 @@ expected_str<qint64> DesktopDeviceFileAccess::writeFileContents(const FilePath &
     qint64 res = file.write(data);
     if (res != data.size())
         return make_unexpected(
-            Tr::tr("Could not write to file \"%1\" (only %2 of %n byte(s) written).")
+            Tr::tr("Could not write to file \"%1\" (only %2 of %n byte(s) written).",
+                   nullptr,
+                   data.size())
                 .arg(filePath.toUserOutput())
-                .arg(res)
-                .arg(data.size()));
+                .arg(res));
     return res;
 }