Adapt test case to match current set of emitted warnings. (or lack

thereof.)

PR 14739 injected the new message that this removes from one test
case: borrowck-vec-pattern-loan-from-mut.rs

When reviewing the test case, I was not able to convince myself that
the error message was a legitimate thing to start emitting.  Niko did
not see an obvious reason for it either, so I am going to remove it
and wait for someone (maybe Cameron Zwarich) to explain to me why we
should be emitting it.

0 files changed, 0 insertions, 0 deletions