repopick: Try to fast-forward first

Change-Id: I4890ce8075556eb3f57d89c283543f620f39fa02
diff --git a/build/tools/repopick.py b/build/tools/repopick.py
index 3c7c06c..7c6bf15 100755
--- a/build/tools/repopick.py
+++ b/build/tools/repopick.py
@@ -448,7 +448,7 @@
                 sys.exit(result)
         # Perform the cherry-pick
         if not args.pull:
-            cmd = ['git cherry-pick FETCH_HEAD']
+            cmd = ['git cherry-pick --ff FETCH_HEAD']
             if args.quiet:
                 cmd_out = open(os.devnull, 'wb')
             else: