net: fixup address-space warnings in compat_mc_{get,set}sockopt()

Add __user attributes in some of the casts in this function to avoid
the following sparse warnings:

net/compat.c:592:57: warning: cast removes address space of expression
net/compat.c:592:57: warning: incorrect type in initializer (different address spaces)
net/compat.c:592:57:    expected struct compat_group_req [noderef] <asn:1>*gr32
net/compat.c:592:57:    got void *<noident>
net/compat.c:613:65: warning: cast removes address space of expression
net/compat.c:613:65: warning: incorrect type in initializer (different address spaces)
net/compat.c:613:65:    expected struct compat_group_source_req [noderef] <asn:1>*gsr32
net/compat.c:613:65:    got void *<noident>
net/compat.c:634:60: warning: cast removes address space of expression
net/compat.c:634:60: warning: incorrect type in initializer (different address spaces)
net/compat.c:634:60:    expected struct compat_group_filter [noderef] <asn:1>*gf32
net/compat.c:634:60:    got void *<noident>
net/compat.c:672:52: warning: cast removes address space of expression
net/compat.c:672:52: warning: incorrect type in initializer (different address spaces)
net/compat.c:672:52:    expected struct compat_group_filter [noderef] <asn:1>*gf32
net/compat.c:672:52:    got void *<noident>
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/compat.c

@@ -525,7 +525,7 @@ int compat_mc_setsockopt(struct sock *sock, int level, int optname,
 	case MCAST_JOIN_GROUP:
 	case MCAST_LEAVE_GROUP:
 	{
-		struct compat_group_req __user *gr32 = (void *)optval;
+		struct compat_group_req __user *gr32 = (void __user *)optval;
 		struct group_req __user *kgr =
 			compat_alloc_user_space(sizeof(struct group_req));
 		u32 interface;
@@ -546,7 +546,7 @@ int compat_mc_setsockopt(struct sock *sock, int level, int optname,
 	case MCAST_BLOCK_SOURCE:
 	case MCAST_UNBLOCK_SOURCE:
 	{
-		struct compat_group_source_req __user *gsr32 = (void *)optval;
+		struct compat_group_source_req __user *gsr32 = (void __user *)optval;
 		struct group_source_req __user *kgsr = compat_alloc_user_space(
 			sizeof(struct group_source_req));
 		u32 interface;
@@ -567,7 +567,7 @@ int compat_mc_setsockopt(struct sock *sock, int level, int optname,
 	}
 	case MCAST_MSFILTER:
 	{
-		struct compat_group_filter __user *gf32 = (void *)optval;
+		struct compat_group_filter __user *gf32 = (void __user *)optval;
 		struct group_filter __user *kgf;
 		u32 interface, fmode, numsrc;
 
@@ -605,7 +605,7 @@ int compat_mc_getsockopt(struct sock *sock, int level, int optname,
 	char __user *optval, int __user *optlen,
 	int (*getsockopt)(struct sock *, int, int, char __user *, int __user *))
 {
-	struct compat_group_filter __user *gf32 = (void *)optval;
+	struct compat_group_filter __user *gf32 = (void __user *)optval;
 	struct group_filter __user *kgf;
 	int __user	*koptlen;
 	u32 interface, fmode, numsrc;