fix typo in mount.go
@@ -83,7 +83,7 @@ type TmpfsOptions struct {
// Size sets the size of the tmpfs, in bytes.
//
// This will be converted to an operating system specific value
- // depending on the host. For example, on linux, it will be convered to
+ // depending on the host. For example, on linux, it will be converted to
// use a 'k', 'm' or 'g' syntax. BSD, though not widely supported with
// docker, uses a straight byte value.
//
