startop: Fix the if condition to prevent duplicate filename for file id

0 in host compiler.

Test: pytest
Bug: 140655545
Change-Id: I952db4cf06060483cfcf8e42352324ad0d710d3b

startop/scripts/iorap/compiler_ri.py

@@ -139,7 +139,9 @@ def build_protobuf(page_runs, inode2filename, filters=[]):
       continue
 
     file_id = file_id_map.get(filename)
-    if not file_id:
+    # file_id could 0, which satisfies "if file_id" and causes duplicate
+    # filename for file id 0.
+    if file_id is None:
       file_id = file_id_counter
       file_id_map[filename] = file_id_counter
       file_id_counter = file_id_counter + 1