[PATCH v2] mm: Fixed incorrect comment for _kmem_cache_create function

[zhaoxinchao <ChrisXinchao@outlook.com>]

From: zhaoxinchao <chrisxinchao@outlook.com>

Actually __kmem_cache_create() returns a status :
0 is success
nonezero are failed.

This function has three return positions. In addition to successfully
return 0, the first failed position will return - E2BIG, and the second
position will return nonzero value for setup_cpu_cache function failure.

Signed-off-by: zhaoxinchao <chrisxinchao@outlook.com>
---
 mm/slab.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/mm/slab.c b/mm/slab.c
index edbe722fb..399daa4d0 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1893,7 +1893,12 @@ static bool set_on_slab_cache(struct kmem_cache *cachep,
  * @cachep: cache management descriptor
  * @flags: SLAB flags
  *
- * Returns a ptr to the cache on success, NULL on failure.
+ * Returns zero on success, nonzero on failure.
+ * This function has three return positions.
+ * In addition to successfully return 0, the
+ * first failed position will return - E2BIG,
+ * and the second position will return nonzero
+ * value for setup_cpu_cache function failure.
  * Cannot be called within an int, but can be interrupted.
  * The @ctor is run when new pages are allocated by the cache.
  *
-- 
2.39.2