savefig does put the correct dpi in the metadata of jpeg

Bug summary

When I save a figure using savefig with a specified dpi argument, the resulting figure is not saved at that resolution.

Code for reproduction

I am saving the figure like this:

bp.get_figure().savefig('../figures/domains_5.jpg', dpi=200)

where bp is the axes of my figure.

Actual outcome

I get a figure saved to 72dpi

Expected outcome

I was expecting a figure at 200dpi

Matplotlib version

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