should not emit fsnotify watcher error for files match excluded_files pattern

[newly12]

Describe the enhancement:
as title

Describe a specific use case for the enhancement or feature:
warning errors are flooding while there is no way to stop it, sample logs is attached as below, some paths of source code in the stack trace are masked.

2020-09-24T02:24:13.740Z        WARN    [file_integrity]        file_integrity/eventreader_fsnotify.go:151      fsnotify watcher error  {"error": "failed to visit created path '/run/containerd/io.containerd.runtime.v1.linux/k8s.io/2e29f16a651a5b6a94365a3132b563a2c3362f5546972fdc783f3d6071542831/rootfs/etc/runit/runsvdir/default/mcelog/supervise/stat.new': path component stat.new not found in /run/containerd/io.containerd.runtime.v1.linux/k8s.io/2e29f16a651a5b6a94365a3132b563a2c3362f5546972fdc783f3d6071542831/rootfs/etc/runit/runsvdir/default/mcelog/supervise/stat.new", "errorVerbose": "path component stat.new not found in /run/containerd/io.containerd.runtime.v1.linux/k8s.io/2e29f16a651a5b6a94365a3132b563a2c3362f5546972fdc783f3d6071542831/rootfs/etc/runit/runsvdir/default/mcelog/supervise/stat.new\nfailed to visit created path '/run/containerd/io.containerd.runtime.v1.linux/k8s.io/2e29f16a651a5b6a94365a3132b563a2c3362f5546972fdc783f3d6071542831/rootfs/etc/runit/runsvdir/default/mcelog/supervise/stat.new'\ngit.luolix.top/elastic/beats/v7/auditbeat/module/file_integrity/monitor.(*recursiveWatcher).forwardEvents\n\t/go/src/xxx/xxx/beats-xxx/vendor/github.com/elastic/beats/v7/auditbeat/module/file_integrity/monitor/recursive.go:168\nruntime.goexit\n\t/usr/local/go/src/runtime/asm_amd64.s:1373"}

[elasticmachine]

Pinging @elastic/integrations-services (Team:Services)

[elasticmachine]

Pinging @elastic/siem (Team:SIEM)