Fix ubsan warnings for i386 build
* mpi/mpicoder.c (_gcry_mpi_set_buffer) [BYTES_PER_MPI_LIMB == 4]: Cast "*p--" values to mpi_limb_t before left shifting. * tests/t-lock.c (main): Cast 'time(NULL)' to unsigned type.
- Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>