STYLE: 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.

build/cmake/tests/CMakeLists.txt

@@ -52,4 +52,4 @@ target_link_libraries(fuzzer libzstd_static)
 if (UNIX)
     add_executable(paramgrill ${PROGRAMS_DIR}/benchfn.c ${PROGRAMS_DIR}/benchzstd.c ${PROGRAMS_DIR}/datagen.c ${PROGRAMS_DIR}/util.c ${TESTS_DIR}/paramgrill.c)
     target_link_libraries(paramgrill libzstd_static m) #m is math library
-endif (UNIX)
+endif ()