Don't check for FEC offset if fec is disabled

Test: th
Bug: 194661607
Bug: 194779085

Change-Id: I0e37136313914f1ee9a4eae0e5db59807adc7dc5
Merged-In: I0e37136313914f1ee9a4eae0e5db59807adc7dc5
diff --git a/payload_consumer/filesystem_verifier_action.cc b/payload_consumer/filesystem_verifier_action.cc
index 22c8e0b..8b39f6d 100644
--- a/payload_consumer/filesystem_verifier_action.cc
+++ b/payload_consumer/filesystem_verifier_action.cc
@@ -358,8 +358,10 @@
 
   offset_ = 0;
   filesystem_data_end_ = partition_size_;
-  CHECK_LE(partition.hash_tree_offset, partition.fec_offset)
-      << " Hash tree is expected to come before FEC data";
+  if (partition.fec_offset > 0) {
+    CHECK_LE(partition.hash_tree_offset, partition.fec_offset)
+        << " Hash tree is expected to come before FEC data";
+  }
   if (partition.hash_tree_offset != 0) {
     filesystem_data_end_ = partition.hash_tree_offset;
   } else if (partition.fec_offset != 0) {