samples/seccomp: fix 64-bit comparison macros

samples/seccomp: fix 64-bit comparison macros

BugLink: http://bugs.launchpad.net/bugs/1673538
commit 916cafdc95843fb9af5fd5f83ca499d75473d107 upstream.

There were some bugs in the JNE64 and JLT64 comparision macros. This fixes
them, improves comments, and cleans up the file while we are at it.

Reported-by: Stephen Röttger <sroettger@google.com>
Signed-off-by: Mathias Svensson <idolf@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>