RELNOTES: Fix KMSAN entry

The lead digit was lost in 05eba8e068c1 making it impossible to find the
commit.

The two subsequent RELNOTES commits gave one less digit of the commit
hash, which is what git rev-parse --short thinks the minimal length is,
but keep them to align with other entries.

Fixes: 05eba8e068c1
Differential Revision: https://reviews.freebsd.org/D32595