hping: set platforms = all

From http://www.hping.org/:

"Hping works on the following unix-like systems: Linux, FreeBSD,
NetBSD, OpenBSD, Solaris, MacOs X, Windows."

Changed files
+1
pkgs
tools
networking
hping
+1
pkgs/tools/networking/hping/default.nix
···
description = "A command-line oriented TCP/IP packet assembler/analyzer";
homepage = "http://www.hping.org/";
license = stdenv.lib.licenses.gpl2;
+
platforms = stdenv.lib.platforms.all;
};
}