Fix a concurrent map write panic in auditd module (elastic#8158)

Update github.com/elastic/go-libaudit to v0.4.0, which includes the fix
for this issue.

CHANGELOG.asciidoc

@@ -50,6 +50,7 @@ https://github.com/elastic/beats/compare/v6.4.0...master[Check the HEAD diff]
 - Fixed a data race in the file_integrity module. {issue}8009[8009]
 - Fixed a deadlock in the file_integrity module. {pull}8027[8027]
 - Fixed the RPM by designating the config file as configuration data in the RPM spec. {issue}8075[8075]
+- Fixed a concurrent map write panic in the auditd module. {pull}8158[8158]
 
 *Filebeat*
 

NOTICE.txt

@@ -401,7 +401,8 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 --------------------------------------------------------------------
 Dependency: github.com/elastic/go-libaudit
-Revision: ec7a7253716958d85ea854cbef4aaffcd6cbd50b
+Version: v0.4.0
+Revision: 39073a2988f718067d85d27a4d18b1b57de5d947
 License type (autodetected): Apache-2.0
 ./vendor/github.com/elastic/go-libaudit/LICENSE.txt:
 --------------------------------------------------------------------

vendor/vendor.json

@@ -379,34 +379,44 @@
 			"revisionTime": "2016-08-05T00:47:13Z"
 		},
 		{
-			"checksumSHA1": "D/7cJ8oboLL/gQxr57kfvDBtMZE=",
+			"checksumSHA1": "vNnw1bUS8Ct+8H64QuA2DWRJ9SQ=",
 			"path": "github.com/elastic/go-libaudit",
-			"revision": "ec7a7253716958d85ea854cbef4aaffcd6cbd50b",
-			"revisionTime": "2018-08-07T15:01:12Z"
+			"revision": "39073a2988f718067d85d27a4d18b1b57de5d947",
+			"revisionTime": "2018-08-29T20:25:13Z",
+			"version": "v0.4.0",
+			"versionExact": "v0.4.0"
 		},
 		{
-			"checksumSHA1": "QTR02jPgqq2P6mZKMWUdAUQPVbQ=",
+			"checksumSHA1": "NRGAFJY7u1wYeXtNzLlI5/MnBMQ=",
 			"path": "github.com/elastic/go-libaudit/aucoalesce",
-			"revision": "ec7a7253716958d85ea854cbef4aaffcd6cbd50b",
-			"revisionTime": "2018-08-07T15:01:12Z"
+			"revision": "39073a2988f718067d85d27a4d18b1b57de5d947",
+			"revisionTime": "2018-08-29T20:25:13Z",
+			"version": "v0.4.0",
+			"versionExact": "v0.4.0"
 		},
 		{
 			"checksumSHA1": "6OK3lLgocjmIUyLo8xNhYGpwE1E=",
 			"path": "github.com/elastic/go-libaudit/auparse",
-			"revision": "ec7a7253716958d85ea854cbef4aaffcd6cbd50b",
-			"revisionTime": "2018-08-07T15:01:12Z"
+			"revision": "39073a2988f718067d85d27a4d18b1b57de5d947",
+			"revisionTime": "2018-08-29T20:25:13Z",
+			"version": "v0.4.0",
+			"versionExact": "v0.4.0"
 		},
 		{
 			"checksumSHA1": "zGv2vPwSLoFCRt1kcD81pBzTo+0=",
 			"path": "github.com/elastic/go-libaudit/rule",
-			"revision": "ec7a7253716958d85ea854cbef4aaffcd6cbd50b",
-			"revisionTime": "2018-08-07T15:01:12Z"
+			"revision": "39073a2988f718067d85d27a4d18b1b57de5d947",
+			"revisionTime": "2018-08-29T20:25:13Z",
+			"version": "v0.4.0",
+			"versionExact": "v0.4.0"
 		},
 		{
 			"checksumSHA1": "5C083BvwcAVSKquRXbxXa950/wE=",
 			"path": "github.com/elastic/go-libaudit/rule/flags",
-			"revision": "ec7a7253716958d85ea854cbef4aaffcd6cbd50b",
-			"revisionTime": "2018-08-07T15:01:12Z"
+			"revision": "39073a2988f718067d85d27a4d18b1b57de5d947",
+			"revisionTime": "2018-08-29T20:25:13Z",
+			"version": "v0.4.0",
+			"versionExact": "v0.4.0"
 		},
 		{
 			"checksumSHA1": "3jizmlZPCyo6FAZY8Trk9jA8NH4=",