bfin_jtag_comm: clean up printk usage

The original patch garned some feedback and a v2 was posted, but that
version seems to have been missed when merging the driver.

At any rate, this cleans up the printk usage as suggested by Jiri Slaby.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>