Fix a typo which had caused wrong LuaJIT OS to be detected.

Source/ThirdParty/LuaJIT/CMakeLists.txt

@@ -217,7 +217,7 @@ elseif (MINGW)
 elseif (NOT TARGET_SYS)
     set (TARGET_SYS ${HOST_SYS})
 endif ()
-if (NOT HOST_SYST STREQUAL TARGET_SYS)
+if (NOT HOST_SYS STREQUAL TARGET_SYS)
     if (TARGET_SYS STREQUAL Windows)
         set (HOST_XCFLAGS ${HOST_XCFLAGS} -malign-double -DLUAJIT_OS=LUAJIT_OS_WINDOWS)
     elseif (TARGET_SYS STREQUAL Linux)