Fix invalid xbmcgui.LOGERROR in Radarr/Sonarr error paths

[Pihaar]

The error-logging calls in the main Radarr and Sonarr flows pass
xbmcgui.LOGERROR, which does not exist. The Kodi log-level constants
live in the xbmc module, not xbmcgui.

common.log() forwards the level to xbmc.log(), so evaluating
xbmcgui.LOGERROR at the call site raises
AttributeError: module 'xbmcgui' has no attribute 'LOGERROR'. This
happens on every failure path (failed lookup, add, command, or an
exception): instead of the intended error message the user gets a
script error, and the surrounding except then calls
log(..., xbmcgui.LOGERROR) again, raising a second uncaught
AttributeError. The happy path is unaffected.

The helper/test functions already use the correct xbmc.LOGERROR
(for example radarr.py:28, 45, 51), so this is an inconsistency.

Fix: use xbmc.LOGERROR at the affected sites. xbmc is already
imported in both files, so no other change is needed.

Affected lines:

• resources/lib/radarr.py: 117, 130, 147, 182, 186
• resources/lib/sonarr.py: 263, 299, 321, 375, 382

Verified on Kodi 22: xbmcgui.LOGERROR raises AttributeError,
xbmc.LOGERROR is 3, and calling the addon's
common.log(msg, xbmc.LOGERROR) works.