slqb: add common slab debug bits

This is a simple copy&paste from slub.c:

- lockdep annotation
- might sleep annotation
- fault injection

CC: Nick Piggin <nickpiggin@yahoo.com.au>
CC: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

mm/slqb.c

@@ -19,6 +19,7 @@
 #include <linux/ctype.h>
 #include <linux/kallsyms.h>
 #include <linux/memory.h>
+#include <linux/fault-inject.h>
 
 /*
  * TODO
@@ -1541,6 +1542,12 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
 
 	gfpflags &= gfp_allowed_mask;
 
+	lockdep_trace_alloc(gfpflags);
+	might_sleep_if(gfpflags & __GFP_WAIT);
+
+	if (should_failslab(s->objsize, gfpflags))
+		return NULL;
+
 again:
 	local_irq_save(flags);
 	object = __slab_alloc(s, gfpflags, node);