On OS X, where #pragma ident and #ident aren't supported, the
use of a static const star that was never used was generating
a warning (and, it should be noted, was useless, because the
compiler would optimize it away). Fix up the ident declaration
so that it is only created once in libmpi_mpifh.la.
Signed-off-by: Brian Barrett <bbarrett@amazon.com>