simplify finding of windows SDK in configure.ac

find_winsdk() is never called with a parameter

Change-Id: Ib0b0e5053a3bf792b66832d96ebf771251a24c1f
Reviewed-on: https://gerrit.libreoffice.org/13167Tested-by: LibreOffice gerrit bot <gerrit@libreoffice.org>
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>

configure.ac

@@ -5087,13 +5087,7 @@ find_winsdk()
 
     unset winsdktest
 
-    if test -n "$1"; then
-        sdkversions=$1
-    else
-        sdkversions="$WINDOWS_SDK_ACCEPTABLE_VERSIONS"
-    fi
-
-    for ver in $sdkversions; do
+    for ver in $WINDOWS_SDK_ACCEPTABLE_VERSIONS; do
         find_winsdk_version $ver
         if test -n "$winsdktest"; then
             return