Add missing semicolon argument.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>

open_pdks/post-open_pdks.sh

diff --git a/open_pdks/post-open_pdks.sh b/open_pdks/post-open_pdks.sh
index 4b55c43..bda3828 100755
--- a/open_pdks/post-open_pdks.sh
+++ b/open_pdks/post-open_pdks.sh
@@ -24,5 +24,5 @@
 find /host/out/pdk-* -name '*.mag' -exec sed -i -e's/timestamp [0-9]\+/timestamp 0/' \{\} \+
 
 # Clear timestamps in GDS files
-find /host/out/pdk-* -name '*.gds' -exec /host/git/builder/open_pdks/gds_change_date.py 1 0 \{\}
+find /host/out/pdk-* -name '*.gds' -exec /host/git/builder/open_pdks/gds_change_date.py 1 0 \{\} \;
 #find out/pdk-* -name '*.gds' -print | parallel -v /host/git/builder/open_pdks/gds_change_date.py 1 0 \{\}