mount: replace mountinfo handling with moby/sys/mountinfo

Trying to reduce duplicated effort in maintaining a mountinfo
parser, this patch replaces the local implementation with the
implementation in github.com/moby/sys, which is actively maintained
and contains various optimizations.

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

vendor/github.com/moby/sys/mountinfo/mountinfo_windows.go

@@ -0,0 +1,10 @@
+package mountinfo
+
+func parseMountTable(_ FilterFunc) ([]*Info, error) {
+	// Do NOT return an error!
+	return nil, nil
+}
+
+func mounted(_ string) (bool, error) {
+	return false, nil
+}