internal/diff/lcs: fix shell format error
internal/diff/lcs: fix shell format error

Change-Id: Id333dd169c7b7a54823bd077ce677fc74b4eb057
GitHub-Last-Rev: f16abccaad199cf229fb2e6dbf126441b4e573b5
GitHub-Pull-Request: golang/tools#397
Reviewed-on: https://go-review.googlesource.com/c/tools/+/431136
Run-TryBot: Robert Findley <9179eee875d1ee628c37fb47d7e749e855ffd21f@google.com>
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Robert Findley <9179eee875d1ee628c37fb47d7e749e855ffd21f@google.com>
Reviewed-by: Bryan Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>
gopls-CI: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Auto-Submit: Bryan Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>

golang/tools,golang/tools,golang/tools,golang/tools,golang/tools