xtensa: clean up stpill_registers

- remove unused asm parameters;
- fix EXCM bit setting in the PS SR during _spill_registers call.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

arch/xtensa/include/asm/traps.h

@@ -22,10 +22,9 @@ extern void do_unhandled(struct pt_regs *regs, unsigned long exccause);
 
 static inline void spill_registers(void)
 {
-	unsigned int a0, ps;
 
 	__asm__ __volatile__ (
-		"movi	a14, " __stringify(PS_EXCM_BIT | LOCKLEVEL) "\n\t"
+		"movi	a14, "__stringify((1 << PS_EXCM_BIT) | LOCKLEVEL)"\n\t"
 		"mov	a12, a0\n\t"
 		"rsr	a13, sar\n\t"
 		"xsr	a14, ps\n\t"
@@ -35,7 +34,7 @@ static inline void spill_registers(void)
 		"mov	a0, a12\n\t"
 		"wsr	a13, sar\n\t"
 		"wsr	a14, ps\n\t"
-		: : "a" (&a0), "a" (&ps)
+		: :
 #if defined(CONFIG_FRAME_POINTER)
 		: "a2", "a3", "a4",       "a11", "a12", "a13", "a14", "a15",
 #else