t7610: unsuppress output

t7610: unsuppress output

The output for commands used to be suppressed by redirecting both stdout
and stderr to /dev/null. However, this should not happen since the
output is useful for debugging and, without the "-v" flag, test scripts
don't output anyway.

Unsuppress the output by removing the redirections to /dev/null.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>