Allow source build to be an extracted target_files

common.LoadInfoDict() already supports loading from extracted
directories, just use it.

Test: generate an incremental OTA where both inputs are directories
Bug: 227848550
Bug: 277028723
Change-Id: Iedba831bb4d65d971df6b2ac95279e3234a02e2f
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index 04ef5ef..afbe81a 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -525,8 +525,7 @@
 
 
 def ParseInfoDict(target_file_path):
-  with zipfile.ZipFile(target_file_path, 'r', allowZip64=True) as zfp:
-    return common.LoadInfoDict(zfp)
+  return common.LoadInfoDict(target_file_path)
 
 
 def GetTargetFilesZipForCustomVABCCompression(input_file, vabc_compression_param):