cmake: Remove "conditions" from endif

See https://cmake.org/cmake/help/latest/command/endif.html and
https://cmake.org/cmake/help/latest/command/if.html.

If the else/endif condition does not match the if condition verbatim,
an error is produced on some versions of cmake. This change removes
these "legacy conditions."

hlsl/CMakeLists.txt

@@ -56,4 +56,4 @@ if(ENABLE_GLSLANG_INSTALL)
                 ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
     endif()
 	install(EXPORT HLSLTargets DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake)
-endif(ENABLE_GLSLANG_INSTALL)
+endif()