extract_utils: Fix extraction of "empty" partitions

* Any device with an LP entry in super for an empty partition
  (e.g. as Moto commonly does) currently errors out after
  I5c6c2f94e0557442b686ddf418559e44787f8177 (extract_utils: do not
  use ProcessPoolExecutor() for IO-bound tasks).
* The failure was previously masked by ProcessPoolExecutor silently
  swallowing unretireved Future exceptions.
* Just try/except and print a warning instead.

Change-Id: I790db409e35bf11cb94673013fad58e1feab29f6

Author: npjohnson

extract_utils/extract.py

@@ -483,12 +483,15 @@ def extract_all_partitions(dump_dir: str, ctx: ExtractCtx):
 
     while partitions:
         for partition in partitions:
-            if partition == 'recovery':
-                extract_recovery_partition(partition, dump_dir)
-            elif partition in firmware_partitions:
-                extract_firmware_partition(partition, dump_dir)
-            else:
-                extract_partition(partition, dump_dir)
+            try:
+                if partition == 'recovery':
+                    extract_recovery_partition(partition, dump_dir)
+                elif partition in firmware_partitions:
+                    extract_firmware_partition(partition, dump_dir)
+                else:
+                    extract_partition(partition, dump_dir)
+            except Exception as e:
+                print(f'Warning: Failed to extract partition {partition}: {e}')
 
         found_partitions = find_partitions(dump_dir, ctx)
         partitions = find_alternate_partitions(partitions, found_partitions)