fix NOT statement

deploy/cpp/CMakeLists.txt

@@ -61,7 +61,7 @@ if (NOT DEFINED PADDLE_DIR OR ${PADDLE_DIR} STREQUAL "")
     message(FATAL_ERROR "please set PADDLE_DIR with -DPADDLE_DIR=/path/paddle_influence_dir")
 endif()
 
-if (${CMAKE_SYSTEM_PROCESSOR} NOT STREQUAL "aarch64")
+if (NOT (${CMAKE_SYSTEM_PROCESSOR} STREQUAL "aarch64"))
   if (NOT DEFINED OPENCV_DIR OR ${OPENCV_DIR} STREQUAL "")
     message(FATAL_ERROR "please set OPENCV_DIR with -DOPENCV_DIR=/path/opencv")
   endif()