- There is no such thing as a socket structure. sockets are integers.

I'm assuming that the comment was regarding socket address structures, so
  correct the comment about pre-zero'ing socket structures to recommend
  pre-zero'ing socket address structures.
- Fix some minor grammar nits.
- This isn't directly submitted by the PR below but is related to it and was
  inspired by it.

PR:		31704

lib/libc/sys/bind.2

@@ -65,8 +65,8 @@ needed (using
 The rules used in address binding vary between communication domains.
 Consult the manual entries in section 4 for detailed information.
 .Pp
-For maximum portability, you should always zero-out the socket structure
-before populating it, before passing it to
+For maximum portability, you should always zero the socket address structure
+before populating it and passing it to
 .Fn bind .
 .Sh RETURN VALUES
 .Rv -std bind