inet/net-internal.h: Fix uninitalised clntudp_call() variable

The total_deadline variable inside the clntudp_call() function inside
sunrpc/clnt_udp.c can cause uninitalised variable warnings when building
with GCC 8.3 or 9.2 on a platform with a 64-bit tv_nsec on a 32-bit
architecture.  To fix the warning let's use the DIAG_* macros to hide the
warning.

A GCC bug case has also been submitted:
    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91691



2019-09-24  Alistair Francis  <alistair.francis@wdc.com>

	* inet/net-internal.h: Fix uninitalised clntudp_call() variable.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>