Fix errors for high version GPU.

ISSUE=4622423

git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1503 1ad973e4-5ce8-4261-8a94-b56d1f490c56

cmake/flags.cmake

@@ -75,12 +75,13 @@ endforeach()
 # So, don't set these flags here.
 
 foreach(capability 30 35 50)
-    list(APPEND __arch_flags "-gencode arch=compute_${capability},code=sm_${capability}")
+    list(APPEND __arch_flags " -gencode arch=compute_${capability},code=sm_${capability}")
 endforeach()
 
+message(${__arch_flags})
 if (CUDA_VERSION VERSION_GREATER "7.0")
-    list(APPEND __arch_flags "-gencode arch=compute_52,code=sm_52")
+    list(APPEND __arch_flags " -gencode arch=compute_52,code=sm_52")
 endif()
 
-set(CUDA_NVCC_FLAGS ${__arch_flags} ${CUDA_NVCC_FLAGS})
 
+set(CUDA_NVCC_FLAGS ${__arch_flags} ${CUDA_NVCC_FLAGS})