Match second recvfrom() definition with the first definition after
  "is equivalent to" that uses NULL instead of 0.

  Signed-off-by: wcampbell [off-list ref]
  ---
   man2/recv.2 | 2 +-
   1 file changed, 1 insertion(+), 1 deletion(-)

  diff --git a/man2/recv.2 b/man2/recv.2
  index 884c86355..9e8a94bfe 100644
  --- a/man2/recv.2
  +++ b/man2/recv.2
  @@ -309,7 +309,7 @@ socket (see
   .BR connect (2)).
   It is equivalent to the call:
   .PP
  -    recvfrom(fd, buf, len, flags, NULL, 0);
  +    recvfrom(fd, buf, len, flags, NULL, NULL);
   .\"
   .SS recvmsg()
   The
  --
  2.35.1