system/camera: fix 'is_image' uninitialized
@@ -266,7 +266,7 @@ static int nxcamera_cmd_output(FAR struct nxcamera_s *pcam, FAR char *parg)
int ret;
char path[PATH_MAX];
FAR char *ext;
- bool isimage;
+ bool isimage = false;
/* First try to open the device directly */
