Fix some vet errors.

all.bash

 #!/bin/sh
 set -eu
 
+for d in fuse fuse/nodefs fuse/pathfs fuse/test zipfs unionfs \
+    example/hello example/loopback example/zipfs \
+    example/multizip example/unionfs example/memfs \
+    example/autounionfs example/statfs ; \
+do
+  go build -o /dev/null github.com/hanwen/go-fuse/${d}
+done
+
 
 for d in fuse zipfs unionfs fuse/test
 do

fuse/test/loopback_test.go

@@ -373,14 +373,14 @@ func TestLinkForget(t *testing.T) {
 	for _, fn := range []string{"file1", "file2"} {
 		fn = tc.orig + "/" + fn
 		if err := os.Remove(fn); err != nil {
-			t.Fatalf("Remove", err)
+			t.Fatalf("Remove: %v", err)
 		}
 		tc.WriteFile(fn, []byte(c), 0644)
 	}
 	for i, fn := range []string{"file1", "file2"} {
 		fn = tc.mnt + "/" + fn
 		if err := os.Truncate(fn, int64(i)); err != nil {
-			t.Fatalf("Truncate", err)
+			t.Fatalf("Truncate: %v", err)
 		}
 	}