mpih_mod: avoid unintentional conditional branch
* mpi/mpih-const-time.c (_gcry_mpih_mod): Avoid conditional branch on the_bit extraction.
Cherry pick master commit of:
39d5364a9557d6f423de117601cb1e6414814f47
- Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>