Cast the Stat_t.Nlink to uint64 on arm64.

Since the syscall.Stat_t.Nlink is defined as different types on
amd64 and arm64(uint64 and uint32 respectively), we need to cast
them to a unified uint64 type in gVisor code.

Signed-off-by: Haibo Xu <haibo.xu@arm.com>
Change-Id: I7542b99b195c708f3fc49b1cbe6adebdd2f6e96b

pkg/p9/p9.go

@@ -814,7 +814,7 @@ func StatToAttr(s *syscall.Stat_t, req AttrMask) (Attr, AttrMask) {
 		attr.Mode = FileMode(s.Mode)
 	}
 	if req.NLink {
-		attr.NLink = s.Nlink
+		attr.NLink = uint64(s.Nlink)
 	}
 	if req.UID {
 		attr.UID = UID(s.Uid)

runsc/fsgofer/fsgofer.go

@@ -601,7 +601,7 @@ func (l *localFile) GetAttr(_ p9.AttrMask) (p9.QID, p9.AttrMask, p9.Attr, error)
 		Mode:             p9.FileMode(stat.Mode),
 		UID:              p9.UID(stat.Uid),
 		GID:              p9.GID(stat.Gid),
-		NLink:            stat.Nlink,
+		NLink:            uint64(stat.Nlink),
 		RDev:             stat.Rdev,
 		Size:             uint64(stat.Size),
 		BlockSize:        uint64(stat.Blksize),