SINGA-471 Fix the cmake error on some systems

Author: nudles

CMakeLists.txt

@@ -168,9 +168,9 @@ IF (USE_JAVA)
     ADD_SUBDIRECTORY(java)
 ENDIF()
 
-INSTALL(DIRECTORY ${CMAKE_BINARY_DIR}/include DESTINATION ${CMAKE_INSTALL_PREFIX})
+INSTALL(DIRECTORY ${CMAKE_BINARY_DIR}/include DESTINATION ${CMAKE_INSTALL_PREFIX}/)
 INSTALL(DIRECTORY include/singa DESTINATION ${CMAKE_INSTALL_PREFIX}/include/)
-INSTALL(DIRECTORY ${CMAKE_BINARY_DIR}/lib DESTINATION ${CMAKE_INSTALL_PREFIX} PATTERN "*libgtest.a" EXCLUDE )
+INSTALL(DIRECTORY ${CMAKE_BINARY_DIR}/lib DESTINATION ${CMAKE_INSTALL_PREFIX}/ PATTERN "*libgtest.a" EXCLUDE )
 
 INSTALL(CODE "execute_process(COMMAND python setup.py install --prefix=${CMAKE_INSTALL_PREFIX} WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/python)")