lib/test_meminit: add a kmem_cache_alloc_bulk() test

lib/test_meminit: add a kmem_cache_alloc_bulk() test

Make sure allocations from kmem_cache_alloc_bulk() and
kmem_cache_free_bulk() are properly initialized.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexander Potapenko <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Laura Abbott <[email protected]>
Cc: Thibaut Sautereau <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>