misleading comment description in verify_proof function

[levs57]

The comment on this line

halo2/halo2_proofs/src/plonk/verifier.rs

Line 66 in 5678a50

/// Returns a boolean indicating whether or not the proof is valid

suggests that the verify_proof function returns a bool value indicating whether a proof is correct or not.

However, this is misleading, in fact, it returns Result<V::Output, Error>, for a verification strategy V, which, is in fact, not boolean.