unix: gofmt with Go 1.17

Change-Id: I867e6e01c803fec1b5db464db0e88dfe5799cd43
Reviewed-on: https://go-review.googlesource.com/c/sys/+/343249
Trust: Matt Layher <mdlayher@gmail.com>
Run-TryBot: Matt Layher <mdlayher@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
diff --git a/unix/syscall_linux_ppc.go b/unix/syscall_linux_ppc.go
index e475d09..6f1fc58 100644
--- a/unix/syscall_linux_ppc.go
+++ b/unix/syscall_linux_ppc.go
@@ -3,8 +3,7 @@
 // license that can be found in the LICENSE file.
 
 //go:build linux && ppc
-// +build linux
-// +build ppc
+// +build linux,ppc
 
 package unix