[Qemu-devel] checkpatch.pl: warn on C99 comments, but don't fail

[Michael Roth]

Was playing around with Stefan's git hook for checkpatch.pl:

http://blog.vmsplice.net/2011/03/how-to-automatically-run-checkpatchpl.html

which seems really useful butter-finger coders such as myself. But some of 
warnings/errors that have carried over from the kernel have made this approach 
somewhat prohibitive for QEMU code.

These patches add a flag that let's checkpatch.pl exit successfully when we 
only have warnings, while still printing them and encouraging users to fix them.

We also make C99 //comments a warning instead of an error, since they don't 
actually violate QEMU's coding guidelines.