vendor: update cilium/ebpf v0.0.0-20200702112145-1c8d4c9ef775

full diff: a9f01edf17...1c8d4c9ef7

drops support for go1.12, and removes dependency on the golang.org/x/xerrors
transitional package.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/github.com/cilium/ebpf/internal/errors.go

@@ -2,11 +2,11 @@ package internal
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"strings"
 
 	"github.com/cilium/ebpf/internal/unix"
-	"golang.org/x/xerrors"
 )
 
 // ErrorWithLog returns an error that includes logs from the
@@ -16,7 +16,7 @@ import (
 // the log. It is used to check for truncation of the output.
 func ErrorWithLog(err error, log []byte, logErr error) error {
 	logStr := strings.Trim(CString(log), "\t\r\n ")
-	if xerrors.Is(logErr, unix.ENOSPC) {
+	if errors.Is(logErr, unix.ENOSPC) {
 		logStr += " (truncated...)"
 	}