win32 packaging: change gawk syntax in winsparkle updater script

Change-Id: I0a1789fe0746e4db5dadf258b5071402039862db

scripts/winsparkle-xml-updater.sh

@@ -46,7 +46,7 @@ else
 fi
 
 # update URI in <link> field
-gawk -i inplace -v source="${SPARKLE_SOURCE}" '/<link>/{printf "        <link>";
+gawk -v source="${SPARKLE_SOURCE}" '/<link>/{printf "        <link>";
                                              printf source; print "</link>"; next}1' ${SPARKLE_FILE}