bsdinstall: use fat32 for ZFS

[emaste]

Summary

EFI implementations must support all of fat12, fat16, and fat32, but other operating systems typically use fat32 for the EFI system partition. The UFS install path also uses fat32. Follow suit in ZFS.

[imp]

I would, however, like to see this super ugly construct die in a fire. It's way way way over-engineered with little good effect. There's 4 layers of indirections for logging and that's 3 too many.

[emaste]

Use -c 1 consistent with the UFS config.

[emaste]

Upload correct diff

[emaste]

Fixes: 0b7472b3d8d2 ("Mount the EFI system partition (ESP) on newly-installed systems.")

Prior to that commit we newfs'd the ESP with newfs_msdos -F 32 -c 1 -L EFISYS "/dev/$esp" > /dev/null 2>&1

[imp]

I'm a little nervous about -c 1, but it should be adequate across a reasonable range of partition sizes.