Revert "fix(snark_wrapper): compute the correct number of PoW seed ch…

…allenges (#45)"

This reverts commit c2999e1.

crates/snark-wrapper/src/verifier/fri.rs

@@ -37,9 +37,11 @@ pub(crate) fn verify_fri_part<
     transcript.witness_field_elements(cs, &proof.final_fri_monomials[1])?;
 
     if constants.new_pow_bits != 0 {
-        const SEED_BITS: usize = 256;
         // pull enough challenges from the transcript
-        let num_challenges = SEED_BITS.next_multiple_of(GL::CHAR_BITS) / GL::CHAR_BITS;
+        let mut num_challenges = 256 / GL::CHAR_BITS;
+        if num_challenges % GL::CHAR_BITS != 0 {
+            num_challenges += 1;
+        }
         let challenges: Vec<_> = transcript.get_multiple_challenges(cs, num_challenges as usize)?;
         let (is_valid, pow_challenge_limbs) = POW::verify_from_field_elements(cs, challenges, proof.pow_challenge_le, constants.new_pow_bits)?;
         match is_valid.get_value() {