t/t-migrate-info.sh: remove spurious early exit
t/t-migrate-info.sh: remove spurious early exit

The last test in this file has been accidentally skipped since
it was added in commit c8c29f53a52e22c74ab92368c129133b9354f0a1
in PR #2558, so we just ensure it runs by removing the early
exit call.

We also change one use of "wc -l" to "wc -c" to ensure we are
indeed checking that the command outputs nothing; otherwise,
if it happened to output one line, the "echo -n" would remove
the trailing newline and "wc -l" would report zero.

github/git-lfs,github/git-lfs,github/git-lfs