sparc64: Set %l4 properly on trap return after handling signals.

If we did some signal processing, we have to reload the pt_regs
tstate register because it's value may have changed.

In doing so we also have to extract the %pil value contained in there
anre load that into %l4.

This value is at bit 20 and thus needs to be shifted down before we
later write it into the %pil register.

Most of the time this is harmless as we are returning to userspace
and the %pil is zero for that case.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/sparc/kernel/rtrap_64.S

@@ -84,8 +84,9 @@ __handle_signal:
 		ldx			[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
 		sethi			%hi(0xf << 20), %l4
 		and			%l1, %l4, %l4
+		andn			%l1, %l4, %l1
 		ba,pt			%xcc, __handle_preemption_continue
-		 andn			%l1, %l4, %l1
+		 srl			%l4, 20, %l4
 
 		/* When returning from a NMI (%pil==15) interrupt we want to
 		 * avoid running softirqs, doing IRQ tracing, preempting, etc.