IB/hfi1: remove unlikely() from IS_ERR*() condition

"unlikely(IS_ERR_OR_NULL(x))" is excessive. IS_ERR_OR_NULL() already uses
unlikely() internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-8-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Joe Perches <joe@perches.com>
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>