[PATCH -next] ipc/shm: Use ERR_CAST to return error code

[YueHaibing]

Fix gcc warning:
ipc/shm.c: In function 'shm_lock'
ipc/shm.c:210:2: note: randstruct: casting between randomized structure pointer 
types (ssa): 'struct shmid_kernel' and 'struct kern_ipc_perm'

Signed-off-by: YueHaibing <yuehaib...@huawei.com>
---
 ipc/shm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ipc/shm.c b/ipc/shm.c
index 4cd402e..1c65fb3 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -206,7 +206,7 @@ static inline struct shmid_kernel *shm_lock(struct 
ipc_namespace *ns, int id)
         * Callers of shm_lock() must validate the status of the returned ipc
         * object pointer and error out as appropriate.
         */
-       return (void *)ipcp;
+       return ERR_CAST(ipcp);
 }
 
 static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
-- 
1.8.3.1