sw64: do some cleanups for rt_sigframe

Sunway inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I56OLG

--------------------------------

The retcode is unused, since we take __vdso_rt_sigreturn as default
restorer, and redundant err check in setup_rt_frame() can be removed.
Signed-off-by: NHe Sheng <hesheng@wxiat.com>
Signed-off-by: NGu Zitao <guzitao@wxiat.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/sw_64/kernel/signal.c

@@ -34,7 +34,6 @@ asmlinkage void ret_from_sys_call(void);
 struct rt_sigframe {
 	struct siginfo info;
 	struct ucontext uc;
-	unsigned int retcode[3];
 };
 
 /*
@@ -45,10 +44,6 @@ struct rt_sigframe {
 extern char compile_time_assert
 	[offsetof(struct rt_sigframe, uc.uc_mcontext) == 176 ? 1 : -1];
 
-#define INSN_MOV_R30_R16	0x47fe0410
-#define INSN_LDI_R0		0x201f0000
-#define INSN_CALLSYS		0x00000083
-
 static long
 restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
 {
@@ -263,9 +258,6 @@ setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
 	 */
 	r26 = VDSO_SYMBOL(current->mm->context.vdso, rt_sigreturn);
 
-	if (err)
-		return -EFAULT;
-
 	/* "Return" to the handler */
 	regs->r26 = r26;
 	regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler;