[PATCH] pid:fix a return value in alloc_pid

[tangbin]

When I doing a make about linux-next in X86 right now,it prompts a 
warning about "âretvalâ may be used uninitialized in this function
[-Wmaybe-uninitialized]". So I found that undefined 'retval' initially
in alloc_pid(),so the return ERR_PTR(retval) was an uncertain value.
Kmem_cache_alloc() is for sapce,so it will return ERR_PTR(-ENOMEM) if 
unsuccessful.

Signed-off-by: tangbin <tangbin@xxxxxxxxxxxxxxxxxxxx>
---
 kernel/pid.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/pid.c b/kernel/pid.c
index ff6cd67..f214094 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -177,7 +177,7 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *set_tid,
 
 	pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL);
 	if (!pid)
-		return ERR_PTR(retval);
+		return ERR_PTR(-ENOMEM);
 
 	tmp = ns;
 	pid->level = ns->level;
-- 
2.7.4