grc: follow up to gnuradio#7455

Traceback (most recent call last):
  File "/home/schroer/gnuradiocomponents/Test/./callhier.py", line 24, in get_state_directory
    log.warn(f"Found persistent state path '{newpath}', but file does not exist. " +
    ^^^
NameError: name 'log' is not defined

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/schroer/gnuradiocomponents/Test/./callhier.py", line 47, in <module>
    sys.path.append(os.environ.get('GRC_HIER_PATH', get_state_directory()))
                                                    ^^^^^^^^^^^^^^^^^^^^^
  File "/home/schroer/gnuradiocomponents/Test/./callhier.py", line 33, in get_state_directory
    log.warn("Could not retrieve GNU Radio persistent state directory from GNU Radio." +
    ^^^
NameError: name 'log' is not defined

Signed-off-by: Volker Schroer <3470424+dl1ksv@users.noreply.github.com>

grc/core/generator/top_block.py

@@ -154,6 +154,7 @@ def _imports(self):
             output.insert(0, textwrap.dedent("""\
                 import os
                 import sys
+                import logging as log
 
                 def get_state_directory() -> str:
                     oldpath = os.path.expanduser("~/.grc_gnuradio")
@@ -163,7 +164,7 @@ def get_state_directory() -> str:
                         if os.path.exists(newpath):
                             return newpath
                         if os.path.exists(oldpath):
-                            log.warn(f"Found persistent state path '{newpath}', but file does not exist. " +
+                            log.warning(f"Found persistent state path '{newpath}', but file does not exist. " +
                                      f"Old default persistent state path '{oldpath}' exists; using that. " +
                                      "Please consider moving state to new location.")
                             return oldpath
@@ -172,15 +173,15 @@ def get_state_directory() -> str:
                         os.makedirs(newpath, exist_ok=True)
                         return newpath
                     except (ImportError, NameError):
-                        log.warn("Could not retrieve GNU Radio persistent state directory from GNU Radio." +
+                        log.warning("Could not retrieve GNU Radio persistent state directory from GNU Radio. " +
                                  "Trying defaults.")
                         xdgstate = os.getenv("XDG_STATE_HOME", os.path.expanduser("~/.local/state"))
                         xdgcand = os.path.join(xdgstate, "gnuradio")
                         if os.path.exists(xdgcand):
                             return xdgcand
                         if os.path.exists(oldpath):
-                            log.warn(f"Using legacy state path '{oldpath}'. Please consider moving state " +
-                                     f"files to '{newpath}'.")
+                            log.warning(f"Using legacy state path '{oldpath}'. Please consider moving state " +
+                                     f"files to '{xdgcand}'.")
                             return oldpath
                         # neither old, nor new path exist: create new path, return that
                         os.makedirs(xdgcand, exist_ok=True)