BUG: fix missed CMAKE to X11 variable name

Modules/FindX11.cmake

@@ -90,7 +90,7 @@ IF (UNIX)
       IF(NOT CMAKE_HAVE_GETHOSTBYNAME)
         CHECK_LIBRARY_EXISTS("nsl" "gethostbyname" "" CMAKE_LIB_NSL_HAS_GETHOSTBYNAME) 
         IF (CMAKE_LIB_NSL_HAS_GETHOSTBYNAME)
-          SET (CMAKE_X_EXTRA_LIBS ${CMAKE_X_EXTRA_LIBS} -lnsl)
+          SET (X11_X_EXTRA_LIBS ${X11_X_EXTRA_LIBS} -lnsl)
         ELSE (CMAKE_LIB_NSL_HAS_GETHOSTBYNAME)
           CHECK_LIBRARY_EXISTS("bsd" "gethostbyname" "" CMAKE_LIB_BSD_HAS_GETHOSTBYNAME) 
           IF (CMAKE_LIB_BSD_HAS_GETHOSTBYNAME)
@@ -132,7 +132,6 @@ IF (UNIX)
     IF(CMAKE_LIB_ICE_HAS_ICECONNECTIONNUMBER)
       SET (X11_X_PRE_LIBS -lSM -lICE)
     ENDIF(CMAKE_LIB_ICE_HAS_ICECONNECTIONNUMBER)
-
     # Build the final list of libraries.
     SET (X11_LIBRARIES ${X11_X_PRE_LIBS} ${X11_LIBRARIES} ${X11_X_EXTRA_LIBS})
   ENDIF(X11_FOUND)