选择升级包时选择了一个target_files文件，导致升级失败，

这种错误的log会出现如下信息：

Opening update package...
sysutil: failed to read block device from header
sysutil: Map of '@/cache/recovery/block.map' failed
E:failed to map file

说明读取文件头出错，文件很可能不匹配。