powerpc: Eliminate a compile warning in signal_32.c

The second argument of get_sigset_t needed to have the const keyword.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index e7e7aac..1c4eac4 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -105,7 +105,8 @@
 	return copy_to_user(uset, &cset, sizeof(*uset));
 }
 
-static inline int get_sigset_t(sigset_t *set, compat_sigset_t __user *uset)
+static inline int get_sigset_t(sigset_t *set,
+			       const compat_sigset_t __user *uset)
 {
 	compat_sigset_t s32;
 
@@ -187,7 +188,7 @@
 	return copy_to_user(uset, set, sizeof(*uset));
 }
 
-static inline int get_sigset_t(sigset_t *set, sigset_t __user *uset)
+static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset)
 {
 	return copy_from_user(set, uset, sizeof(*uset));
 }