crux-smart-open-line-above: Use crux-move-to-mode-line-start

[muffinmad]

After renaming move-to-mode-line-start to crux-move-to-mode-line-start in dcd693c there are still one usage of old move-to-mode-line-start function.

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Thanks!

[bbatsov]

Thanks for spotting and fixing my mistake!

[muffinmad]

Thanks for spotting and fixing my mistake!

Thank you for the crux!