[validation] Remove error() calls from Invalid() calls

Summary:
This is in preparation for the next commit, which removes the useless
ret parameter from ValidationState::Invalid().

error() is simply a convenience wrapper that calls LogPrintf and returns
false. Call LogPrintf explicitly and substitute the error() call for a
false bool literal.

Partial backport of Core PR15921 : https://github.com/bitcoin/bitcoin/pull/15921/commits/1a37de4b3174d19a6d8691ae07e92b32fdfaef11

Test Plan: ninja check check-functional

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D6876