Fix remote chance of invalid buffer access in write_video.
Support alternate HCI method path (recent "Phoenix BIOS" Toshiba's).
Signal more proc-write errors.
On proc-reads, report errors via printk instead of proc output.
Add log level and driver name prefix to all printk's.
Add missing __init and __exit function attributes.
Be explicit about vars for which code relies on zero-init of BSS.