remove redundant git operation

git fetch and git remote update do the same work, and there is no need
to do it twice. Keep the fetch command since we can explicitly tell it
to pull down tags.

Change-Id: Iac1602ebe7a1a67ad5fecb599cde21f2a312fff4
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

tools/clone_repo.sh

@@ -158,7 +158,6 @@ fi
 
 # Make sure it is up to date compared to the upstream remote.
 (cd $local_dir &&
-        git remote update &&
         git fetch origin --tags
 )