Change regex for hdd errors to be more strict

Its possible for fluentd to match and report false positives with
current regex for hdd errors. The following log example line:
failed to deactivate service binding for container
 jenkins_slave02.1.tijvdstzxrs6gikbwrtu85078" error=
can be catched by the regex and report about the (false positive)
issue will be sent to prometheus. So the new regex must be more strict,
in order to avoid such alerts.

Change-Id: Ieb27ca39a32ad7bf6e1d0e88d564405e460a4f5f
Closes-Bug: PROD-17883

linux/meta/fluentd.yml

@@ -99,11 +99,11 @@ agent:
                     result: metric.out_of_memory
                   - name: Payload
                     regexp: >-
-                      'error.+[sv]d[a-z]+\d*'
+                      'error.*\b[sv]d[a-z]{1,2}\d{0,3}\b.*'
                     result: metric.hdd_errors
                   - name: Payload
                     regexp: >-
-                      '[sv]d[a-z]+\d*.+error'
+                      '\b[sv]d[a-z]{1,2}\d{0,3}\b.*error'
                     result: metric.hdd_errors
           push_to_metric:
             tag: 'metric.**'