fix number of arguments

Modules/CMakeDetermineSystem.cmake

@@ -39,7 +39,7 @@ IF(UNIX)
     ENDIF(${CMAKE_SYSTEM_PROCESSOR} MATCHES "--help")
     SET(CMAKE_UNAME ${CMAKE_UNAME} CACHE INTERNAL "uname command")
     # processor may have double quote in the name, and that needs to be removed
-    STRING(REGEX REPLACE "\"" "" CMAKE_SYSTEM_PROCESSOR ${CMAKE_SYSTEM_PROCESSOR})
+    STRING(REGEX REPLACE "\"" "" CMAKE_SYSTEM_PROCESSOR "${CMAKE_SYSTEM_PROCESSOR}")
   ENDIF(CMAKE_UNAME)
 ELSE(UNIX)
   IF(WIN32)