Fix warnp strings

[gperciva]

No description provided.

[gperciva]

I kept these as separate commits for ease of reviewing, but they should probably be smooshed together in the git history. This can be done in the github interface, or I could rebase them myself.

[cperciva]

Can you add a few lines to STYLE about this? (Probably not necessary to mention "print the name of the right function", but worth saying "write foo rather than foo()" and "no terminating punctuation or line break".)

[gperciva]

Updated

[gperciva]

Oops, there's a few more cases. STYLE now says "no terminating punctuation", but:

$ git grep "warn" | grep -e "?\"" -e "\!\""
crypto/crypto_dh.c:		warn0("Exponent result too large!");
http/http.c:		warn0("HTTP response with major version > 1!");
tests/aws/main.c:		warn0("That should have failed!");
util/entropy.c:			warn0("EOF on /dev/urandom?");

Arguably these case are unusual enough to warrant punctuation, in which case I should modify STYLE.

[cperciva]

Yeah I think those cases deserve their punctuation.