Fix typo, allow SVR4 packages to be built again.

cmake/install_layout.cmake

@@ -86,7 +86,7 @@ IF(UNIX)
     SET(CMAKE_INSTALL_PREFIX ${default_prefix}
       CACHE PATH "install prefix" FORCE)
   ENDIF()
-  SET(VALID_INSTALL_LAYOUTS "RPM" "STANDALONE" "DEB" "SVR5")
+  SET(VALID_INSTALL_LAYOUTS "RPM" "STANDALONE" "DEB" "SVR4")
   LIST(FIND VALID_INSTALL_LAYOUTS "${INSTALL_LAYOUT}" ind)
   IF(ind EQUAL -1)
     MESSAGE(FATAL_ERROR "Invalid INSTALL_LAYOUT parameter:${INSTALL_LAYOUT}."