Remove uint64_t format specifier warnings

[blutack]

There are format build warnings present with GCC 4.8.1 on Linux.

src/core/global.c: In function ‘nn_global_submit_counter’:
src/core/global.c:904:13: warning: format ‘%llu’ expects argument of type ‘long long unsigned int’, but argument 5 has type ‘uint64_t’ [-Wformat=]
             s->socket_name, name, value);
             ^
src/core/global.c:919:17: warning: format ‘%llu’ expects argument of type ‘long long unsigned int’, but argument 8 has type ‘uint64_t’ [-Wformat=]
                 timebuf, value);
                 ^
src/core/global.c:923:17: warning: format ‘%llu’ expects argument of type ‘long long unsigned int’, but argument 8 has type ‘uint64_t’ [-Wformat=]
                 timebuf, value);
                 ^

This patch explicitly casts 'value' to match the format specifier, and results in a clean build.

[tailhook]

Patch seems ok. Can you state that the patch is submitted under MIT license?

[tailhook]

Also what name should I add to the AUTHORS file?

[blutack]

I hereby state that this patch is submitted under the MIT license.
If it's worth adding to AUTHORS for such a trivial fix, could you pop it under Gareth Roberts, blutack at gmail please?

[tailhook]

Applied. Thanks!

[blutack]

You're welcome. Nanomsg is fantastic.