basmgr: Use SvRef::get() instead of &*

Using &* can be problematic if the pointer is null. In this case it
probably doesn’t matter, but using SvRef::get() is probably easier to
understand anyway. This also paves the way for a later compiler plugin
to check for this.

Change-Id: Id539b0e2630013c4f07debf22eaeca1b45403fcd
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/211841
Reviewed-by: Neil Roberts <nroberts@libreoffice.org>
Tested-by: Jenkins

basic/source/basmgr/basmgr.cxx

@@ -1047,7 +1047,7 @@ StarBASIC* BasicManager::AddLib( SotStorage& rStorage, const OUString& rLibName,
         pLibInfo = nullptr;
     }
 
-    return pLibInfo ? &*pLibInfo->GetLib() : nullptr;
+    return pLibInfo ? pLibInfo->GetLib().get() : nullptr;
 
 }