sbin/swapon: allow late swap option with geli swap

[AMDmi3]

Summary

With following in fstab:

/dev/gpt/swap.eli none swap sw,late 0 0

swap will not be enabled, with swapon -aL complaining:

swapon: Invalid option: late

This is incorrect and happens because swap_on_geli_args() which
parses geli arguments out of mount options doesn't expect late or
noauto there. Fix this by explicitly allowing these arguments.

With this fix, I was able to get late geli swap working.

Test Plan

Tested on real box

[jilles]

The idea looks good to me.

I don't like the dead store into p and useless use of strstr() (which is equivalent to strncmp()), although there is precedent in the above line for notrim.

With a slight change of behaviour, else if (strcmp(token, "late") == 0) should be good.

[AMDmi3]

Use proper way of string comparison

[AMDmi3]

Oh, pardon my negligence, I've just copypasted these without examining the code properly. Use strcmp for string comparison, and fix another similar case along the way.