Remove CMake-language block-end command arguments

Remove CMake-language block-end command arguments

Ancient versions of CMake required else(), endif(), and similar block
termination commands to have arguments matching the command starting the
block.  This is no longer the preferred style.

NOTE: MUST USE GNU compliant version of sed
Run the following shell code:

for c in else endif endforeach endfunction endmacro endwhile; do
    echo 's/\b'"$c"'\(\s*\)(.\+)/'"$c"'\1()/'
done >convert.sed \
&& git ls-files -z -- bootstrap '*.cmake' '*.cmake.in' '*CMakeLists.txt' \
   | xargs -0 gsed -i -f convert.sed \
&& rm convert.sed