Use capsicum helpers widely.

[emaste]

For future uploads can you please include context (e.g. git diff -U9999)

usr.bin/cmp/cmp.c

167–170

I think we should generally combine these into one error, e.g. "unable to limit stdio rights". Unless there's some action the user can take based on knowing if it was stdout or stderr that failed, there's no real value in differentiating them.

[oshogbo]

@emaste Sure.
Fix checks.

[oshogbo]

Fix one more string error.

[cem]

usr.bin/elfdump/elfdump.c

575–576

This drops the zero-capability restriction of stdin.

[oshogbo]

Limit STDIN in elfdump as @cem suggested.

[cem]

usr.bin/elfdump/elfdump.c

576–577

Seems odd to mix < 0 and == -1 checks in one if.

[emaste]

I could see future tweaks in some of these but I think this is a good cleanup