fix typo in Function::_unformat_data()

Unused datastr variable looks like a typo. Replace sig with datastr.

Fixes: 345cd37 (bpo-36876: Fix the C analyzer tool. (GH-22841))
Signed-off-by: Elizaveta Tereshkina <teryoshkina.ea@gmail.com>

Author: dhejyuyr

Tools/c-analyzer/c_parser/info.py

@@ -1062,11 +1062,11 @@ def _format_data(cls, fmt, data, extra):
     @classmethod
     def _unformat_data(cls, datastr, fmt=None):
         if fmt in ('line', 'brief'):
-            sig, storage = Signature.from_str(sig)
+            sig, storage = Signature.from_str(datastr)
             return sig, {'storage': storage}
         #elif fmt == 'full':
         elif fmt == 'row':
-            sig, storage = Signature.from_str(sig)
+            sig, storage = Signature.from_str(datastr)
             return sig, {'storage': storage}
         else:
             raise NotImplementedError(fmt)