reference to free variable 'base'

[diamond-lizard]

When batch compiling evil-indent-plus, Emacs warns about:

In evil-indent-plus--geq-p:
evil-indent-plus.el:57:29:Warning: reference to free variable ‘base’

In evil-indent-plus--g-p:
evil-indent-plus.el:63:28:Warning: reference to free variable ‘base’