In BlockImageVerify some commands are undefined, e.g. "erase", "new",
"zero". And we should not error out if the corresponding function
pointer of these commands is null; otherwise we will fail the
verification.
The old code is:
if (cmd->f != nullptr && cmd->f(params) == -1)
return false;
In the last_command_file change the logic was wrongly modified to
if (cmd->f == nullptr)
return false;
...
if (cmd->f(params) == -1)
return false;
Test: sideload an incremental OTA twice on bullhead
Change-Id: I2561c365badb850da0e416629ccd61f0df7da5d7