tools: patman: Handle missing blank line for 'Series-changes'

'Series-changes' uses blank line to indicate its end. If that is
missing, series internal state variable 'in_change' may be wrong.
Correct its state.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
1 file changed