gitk: Fix a couple of bugs
gitk: Fix a couple of bugs

First, if we invalidate the layout for all rows (i.e. from row 0 on),
we were calling undolayout with an empty string as the argument.
Second, the comparison in make_disporder that tests if we need to
call update_arcrows was the wrong way around.

Signed-off-by: Paul Mackerras <19a0ba370c443ba08d20b5061586430ab449ee8c@samba.org>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git