msm: ocmem: Change the return type of the notifier api.

The ocmem notifier API currently works with a void* pointer
for registration and de-registration. Change it to return
a pointer to struct ocmem_notifier which is useful for debug
purposes.

Change-Id: I93af1213624e5da6993514078451f0474af2c89e
Signed-off-by: Naveen Ramaraj <nramaraj@codeaurora.org>
diff --git a/arch/arm/mach-msm/ocmem_notifier.c b/arch/arm/mach-msm/ocmem_notifier.c
index 58ad3d9..4754f44 100644
--- a/arch/arm/mach-msm/ocmem_notifier.c
+++ b/arch/arm/mach-msm/ocmem_notifier.c
@@ -75,7 +75,8 @@
 	return ret;
 }
 
-void *ocmem_notifier_register(int client_id, struct notifier_block *nb)
+struct ocmem_notifier *ocmem_notifier_register(int client_id,
+						struct notifier_block *nb)
 {
 
 	int ret = 0;
@@ -115,13 +116,12 @@
 }
 EXPORT_SYMBOL(ocmem_notifier_register);
 
-int ocmem_notifier_unregister(void *hndl, struct notifier_block *nb)
+int ocmem_notifier_unregister(struct ocmem_notifier *nc_hndl,
+				struct notifier_block *nb)
 {
 
 	int ret = 0;
 
-	struct ocmem_notifier *nc_hndl = (struct ocmem_notifier *) hndl;
-
 	if (!nc_hndl) {
 		pr_err("ocmem: Invalid notification handle\n");
 		return -EINVAL;