ARC: fix spare error

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312082320.VDN5A9hb-lkp@intel.com/
Signed-off-by: Vineet Gupta <vgupta@kernel.org>

Author: vineetgarc

arch/arc/kernel/signal.c

@@ -62,7 +62,7 @@ struct rt_sigframe {
 	unsigned int sigret_magic;
 };
 
-static int save_arcv2_regs(struct sigcontext *mctx, struct pt_regs *regs)
+static int save_arcv2_regs(struct sigcontext __user *mctx, struct pt_regs *regs)
 {
 	int err = 0;
 #ifndef CONFIG_ISA_ARCOMPACT
@@ -75,12 +75,12 @@ static int save_arcv2_regs(struct sigcontext *mctx, struct pt_regs *regs)
 #else
 	v2abi.r58 = v2abi.r59 = 0;
 #endif
-	err = __copy_to_user(&mctx->v2abi, &v2abi, sizeof(v2abi));
+	err = __copy_to_user(&mctx->v2abi, (void const *)&v2abi, sizeof(v2abi));
 #endif
 	return err;
 }
 
-static int restore_arcv2_regs(struct sigcontext *mctx, struct pt_regs *regs)
+static int restore_arcv2_regs(struct sigcontext __user *mctx, struct pt_regs *regs)
 {
 	int err = 0;
 #ifndef CONFIG_ISA_ARCOMPACT