I/OAT: fix null device in call to dev_err()

We can't use the device in a dev_err() after a kzalloc failure or after the
kfree, so simplify it to the pdev that was originally passed in.

Cc: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>