xtensa: xtensa_sigaction doesn't exist

... and struct old_sigaction never used
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/xtensa/include/asm/signal.h

@@ -120,13 +120,6 @@ typedef void (*__sighandler_t)(int);
 #define SIG_ERR	((__sighandler_t)-1)	/* error return from signal */
 
 #ifdef __KERNEL__
-struct old_sigaction {
-	__sighandler_t sa_handler;
-	old_sigset_t sa_mask;
-	unsigned long sa_flags;
-	void (*sa_restorer)(void);
-};
-
 struct sigaction {
 	__sighandler_t sa_handler;
 	unsigned long sa_flags;

arch/xtensa/include/asm/syscall.h

@@ -15,8 +15,6 @@ asmlinkage long xtensa_clone(unsigned long, unsigned long, struct pt_regs*);
 asmlinkage long xtensa_ptrace(long, long, long, long);
 asmlinkage long xtensa_sigreturn(struct pt_regs*);
 asmlinkage long xtensa_rt_sigreturn(struct pt_regs*);
-asmlinkage long xtensa_sigaction(int, const struct old_sigaction*,
-				 struct old_sigaction*);
 asmlinkage long xtensa_sigaltstack(struct pt_regs *regs);
 asmlinkage long sys_rt_sigaction(int,
 				 const struct sigaction __user *,