Fixes some errors/typos/indentation in I2C code


git-svn-id: https://svn.code.sf.net/p/goodfet/code/trunk@1650 12e2690d-a6be-4b82-a7b7-67c4a43b65c8
Do not hardcode app_num 0 in GoodFETMonitorApp.

git-svn-id: https://svn.code.sf.net/p/goodfet/code/trunk@1653 12e2690d-a6be-4b82-a7b7-67c4a43b65c8
Send obviously non-NUL arg to MONITOR_LIST_APPS verb.

Apparently we got a verbose list because '0'!=0, which is far from
intuitive.

git-svn-id: https://svn.code.sf.net/p/goodfet/code/trunk@1654 12e2690d-a6be-4b82-a7b7-67c4a43b65c8
Factorize serial port opening in GoodFETSerialPort().
New USB: add response checks for goodfet protocol, as asserts
Get more info on readcmd error that happens within reset.