LU-5304: use kzalloc/vzalloc instead of [kv]malloc+memset

LU-5304: use kzalloc/vzalloc instead of [kv]malloc+memset

Changed __OBD_VMALLOC_VERBOSE to use vzalloc instead of vmalloc + memset.

Changed LIBCFS_ALLOC_GFP / LIBCFS_ALLOC_POST to use kzalloc or vzalloc,
instead of the regular kmalloc/vmalloc followed by a memset.

Fixed a minor typo (VEROBSE->VERBOSE) in the vicinity.

Change-Id: Ie8ef6036c24bc4557a88d1aa04f34f6ec0c13109
Signed-off-by: Frank Zago <fzago@cray.com>
Reviewed-on: http://review.whamcloud.com/11029
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>