sparc64: tracehook syscall

This changes sparc64 syscall tracing to use the new tracehook.h entry
points.

[ Add assembly changes to force an immediate -ENOSYS return from
  the system call when syscall_trace() returns non-zero at syscall
  entry.  -DaveM ]

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/syscalls.S b/arch/sparc64/kernel/syscalls.S
index db19ed6..a2f2427 100644
--- a/arch/sparc64/kernel/syscalls.S
+++ b/arch/sparc64/kernel/syscalls.S
@@ -162,6 +162,8 @@
 	add	%sp, PTREGS_OFF, %o0
 	call	syscall_trace
 	 clr	%o1
+	brnz,pn	%o0, 3f
+	 mov	-ENOSYS, %o0
 	srl	%i0, 0, %o0
 	srl	%i4, 0, %o4
 	srl	%i1, 0, %o1
@@ -173,6 +175,8 @@
 	add	%sp, PTREGS_OFF, %o0
 	call	syscall_trace
 	 clr	%o1
+	brnz,pn	%o0, 3f
+	 mov	-ENOSYS, %o0
 	mov	%i0, %o0
 	mov	%i1, %o1
 	mov	%i2, %o2