types/features: clarify MountOptions
`MountOptions` does not contain `const void *data` options.
@@ -16,6 +16,7 @@ type Features struct {
// MountOptions is the list of the recognized mount options, e.g., "ro".
// Nil value means "unknown", not "no support for any mount option".
+ // This list does not contain filesystem-specific options passed to mount(2) syscall as (const void *).
MountOptions []string `json:"mountOptions,omitempty"`
// Linux is specific to Linux.
