优化代码，为后面移除java代码做准备

app/src/main/cpp/PhoneDevice.cpp

@@ -775,9 +775,10 @@ bool CPhoneDevice::TakePhoto(const IDevice::PHOTO_INFO& photoInfo, const vector<
     params.orientation = mPhotoInfo.orientation;
 
     // GpioControl::EnableGpio(CMD_SET_CAM_3V3_EN_STATE, true);
+    bool res = false;
     JNIEnv* env = NULL;
     bool didAttachThread = false;
-    bool res = GetJniEnv(m_vm, &env, didAttachThread);
+    res = GetJniEnv(m_vm, &env, didAttachThread);
     if (!res)
     {
         ALOGE("Failed to get JNI Env");
@@ -790,7 +791,6 @@ bool CPhoneDevice::TakePhoto(const IDevice::PHOTO_INFO& photoInfo, const vector<
     }
     TurnOnCameraPower(env);
 
-
     res = true;
     if (mPhotoInfo.mediaType == 0)
     {