usr.bin/procstat: Add missing usage and getopt(3) options

[kdrakehp_zoho.com]

Summary

• Add the missing option 'n' to the getopt(3) string
• Add the missing options 'libxo' and 'N' to the usage message
• Add the missing options 'M' and 'N' to the man-page

Test Plan

The man-page's usage section, the usage message, the getopt(3)
string, and its switch statement were checked against eachother.

[brooks]

usr.bin/procstat/procstat.c

59

At the risk of making usage longer, I think keeping [-a | pid | core ...] on it's own line is clearer.

168

'L' should come before 'l'. style(9) says the case statements should also be sorted, but I know that will create conflicts with D10916 so let's fix that after landing that change.

[kdrakehp_zoho.com]

• Move the last arguments of usage to a separate line
• Correct the order of 'L' and 'l' in the getopt string

[brooks]

Looks good to me. I'll commit shortly.