Cleanup: Change 1 used in bitshifts to 1ULL

Coverity complains about this. It is not a bug as long as we never shift
by more than 31, but it is not terrible to change the constants from 1
to 1ULL as clean up.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13914