Merge add improved comparisons in policy conditionals

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1723
Merged-by: Georgia Garcia <georgia.garcia@canonical.com>

parser/variable.cc

@@ -66,8 +66,6 @@ char *variable::process_var(const char *var)
 		orig++;
 		len--;
 	} else {
-		PERROR("ASSERT: Found var '%s' without variable prefix\n",
-		       var);
 		return NULL;
 	}