pkg/longpath: fix package GoDoc

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

pkg/longpath/longpath.go

@@ -1,7 +1,8 @@
-// longpath introduces some constants and helper functions for handling long paths
-// in Windows, which are expected to be prepended with `\\?\` and followed by either
-// a drive letter, a UNC server\share, or a volume identifier.
-
+// Package longpath introduces some constants and helper functions for handling
+// long paths in Windows.
+//
+// Long paths are expected to be prepended with "\\?\" and followed by either a
+// drive letter, a UNC server\share, or a volume identifier.
 package longpath // import "github.com/docker/docker/pkg/longpath"
 
 import (
@@ -11,7 +12,7 @@ import (
 // Prefix is the longpath prefix for Windows file paths.
 const Prefix = `\\?\`
 
-// AddPrefix will add the Windows long path prefix to the path provided if
+// AddPrefix adds the Windows long path prefix to the path provided if
 // it does not already have it.
 func AddPrefix(path string) string {
 	if !strings.HasPrefix(path, Prefix) {