[PATCH] Array overrun in drivers/infiniband/core/cma.c

This was spotted by coverity #id 1300.  Since the array has only four
elements, we should just use those four.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Acked-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>