x86: get rid of pt_regs argument in sigreturn variants

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index d6bf1f3..38ba7e5 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -597,8 +597,9 @@
  * Do a signal return; undo the signal stack.
  */
 #ifdef CONFIG_X86_32
-unsigned long sys_sigreturn(struct pt_regs *regs)
+unsigned long sys_sigreturn(void)
 {
+	struct pt_regs *regs = current_pt_regs();
 	struct sigframe __user *frame;
 	unsigned long ax;
 	sigset_t set;
@@ -625,8 +626,9 @@
 }
 #endif /* CONFIG_X86_32 */
 
-long sys_rt_sigreturn(struct pt_regs *regs)
+long sys_rt_sigreturn(void)
 {
+	struct pt_regs *regs = current_pt_regs();
 	struct rt_sigframe __user *frame;
 	unsigned long ax;
 	sigset_t set;
@@ -843,8 +845,9 @@
 }
 
 #ifdef CONFIG_X86_X32_ABI
-asmlinkage long sys32_x32_rt_sigreturn(struct pt_regs *regs)
+asmlinkage long sys32_x32_rt_sigreturn(void)
 {
+	struct pt_regs *regs = current_pt_regs();
 	struct rt_sigframe_x32 __user *frame;
 	sigset_t set;
 	unsigned long ax;