Put quotes arounds strings when doing STREQUAL.

Modules/Qt4ConfigDependentSettings.cmake

@@ -43,9 +43,9 @@ ELSE(WIN32)
   # On other platforms, check file extension to know if its static
   IF(QT_QTCORE_LIBRARY_RELEASE)
     GET_FILENAME_COMPONENT(qtcore_lib_ext "${QT_QTCORE_LIBRARY_RELEASE}" EXT)
-    IF(${qtcore_lib_ext} STREQUAL ${CMAKE_STATIC_LIBRARY_SUFFIX})
+    IF("${qtcore_lib_ext}" STREQUAL "${CMAKE_STATIC_LIBRARY_SUFFIX}")
       SET(QT_IS_STATIC 1)
-    ENDIF(${qtcore_lib_ext} STREQUAL ${CMAKE_STATIC_LIBRARY_SUFFIX})
+    ENDIF("${qtcore_lib_ext}" STREQUAL "${CMAKE_STATIC_LIBRARY_SUFFIX}")
   ENDIF(QT_QTCORE_LIBRARY_RELEASE)
   IF(QT_QTCORE_LIBRARY_DEBUG)
     GET_FILENAME_COMPONENT(qtcore_lib_ext "${QT_QTCORE_LIBRARY_DEBUG}" EXT)