Fix comment: find_winsdk apparently does not take any argument

Change-Id: Idd192405810d1e56ded4a42a1bcf972d2e3de904
diff --git a/configure.ac b/configure.ac
index 49480e8..335dc03 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5205,7 +5205,6 @@ find_winsdk_version()

find_winsdk()
{
    # Args: $1 (optional) : list of acceptable SDK versions
    # Return value: From find_winsdk_version

    unset winsdktest