[op] Replace syscall package usage with golang.org/x/sys/unix in pkg/.

The syscall package has been deprecated in favor of golang.org/x/sys.

Note that syscall is still used in the following places:
- pkg/sentry/socket/hostinet/stack.go: some netlink related functionalities
  are not yet available in golang.org/x/sys.
- syscall.Stat_t is still used in some places because os.FileInfo.Sys() still
  returns it and not unix.Stat_t.

Updates #214

PiperOrigin-RevId: 360701387

2 files changed, 3 insertions, 2 deletions

diff --git a/pkg/sentry/kernel/futex/BUILD b/pkg/sentry/kernel/futex/BUILD
index daa2dae76..041e3d4ca 100644
--- a/pkg/sentry/kernel/futex/BUILD
+++ b/pkg/sentry/kernel/futex/BUILD
@@ -54,5 +54,6 @@ go_test(
         "//pkg/context",
         "//pkg/sync",
         "//pkg/usermem",
+        "@org_golang_x_sys//unix:go_default_library",
     ],
 )
diff --git a/pkg/sentry/kernel/futex/futex_test.go b/pkg/sentry/kernel/futex/futex_test.go
index d0128c548..ba7f95d8a 100644
--- a/pkg/sentry/kernel/futex/futex_test.go
+++ b/pkg/sentry/kernel/futex/futex_test.go
@@ -18,10 +18,10 @@ import (
 	"math"
 	"runtime"
 	"sync/atomic"
-	"syscall"
 	"testing"
 	"unsafe"
 
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -488,7 +488,7 @@ func (t *testMutex) Lock() {
 		// Wait for it to be "not locked".
 		w := NewWaiter()
 		err := t.m.WaitPrepare(w, t.d, t.a, true, testMutexLocked, ^uint32(0))
-		if err == syscall.EAGAIN {
+		if err == unix.EAGAIN {
 			continue
 		}
 		if err != nil {