fuse: avoid nil when invalidating entry

fix https://github.com/chrislusf/seaweedfs/issues/2055

go.mod

@@ -62,7 +62,7 @@ require (
 	github.com/prometheus/client_golang v1.3.0
 	github.com/rakyll/statik v0.1.7
 	github.com/rcrowley/go-metrics v0.0.0-20190826022208-cac0b30c2563 // indirect
-	github.com/seaweedfs/fuse v1.1.4
+	github.com/seaweedfs/fuse v1.1.6
 	github.com/seaweedfs/goexif v1.0.2
 	github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e
 	github.com/spaolacci/murmur3 v1.1.0 // indirect

go.sum

@@ -695,6 +695,10 @@ github.com/seaweedfs/fuse v1.1.3 h1:0DddotXwSRGbYG2kynoJyr8GHCy30Z2SpdhP3vdyijY=
 github.com/seaweedfs/fuse v1.1.3/go.mod h1:+PP6WlkrRUG6KPE+Th2EX5To/PjHaFsvqg/UgQ39aj8=
 github.com/seaweedfs/fuse v1.1.4 h1:YYqkK86agMhXRSwR+wFbRI8ikMgk3kL6PNTna1MAHyQ=
 github.com/seaweedfs/fuse v1.1.4/go.mod h1:+PP6WlkrRUG6KPE+Th2EX5To/PjHaFsvqg/UgQ39aj8=
+github.com/seaweedfs/fuse v1.1.5 h1:wyuRh/mDvrvt8ZLDS7YdPSe6nczniSx4sQFs/Jonveo=
+github.com/seaweedfs/fuse v1.1.5/go.mod h1:+PP6WlkrRUG6KPE+Th2EX5To/PjHaFsvqg/UgQ39aj8=
+github.com/seaweedfs/fuse v1.1.6 h1:kvCqaIsCEaYOBw5r8kJPUs9GcbwlIKcScnkPLT7HLuQ=
+github.com/seaweedfs/fuse v1.1.6/go.mod h1:+PP6WlkrRUG6KPE+Th2EX5To/PjHaFsvqg/UgQ39aj8=
 github.com/seaweedfs/goexif v1.0.2 h1:p+rTXYdQ2mgxd+1JaTrQ9N8DvYuw9UH9xgYmJ+Bb29E=
 github.com/seaweedfs/goexif v1.0.2/go.mod h1:MrKs5LK0HXdffrdCZrW3OIMegL2xXpC6ThLyXMyjdrk=
 github.com/secsy/goftp v0.0.0-20190720192957-f31499d7c79a h1:C6IhVTxNkhlb0tlCB6JfHOUv1f0xHPK7V8X4HlJZEJw=