net: lantiq_etop: add blank line after declaration

This patch adds a missing line after the declaration and
fixes the checkpatch warning:

WARNING: Missing a blank line after declarations
+		int desc;
+		for (desc = 0; desc < LTQ_DESC_NUM; desc++)

Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Link: https://lore.kernel.org/r/20211228220031.71576-1-olek2@wp.pl
Signed-off-by: Jakub Kicinski <kuba@kernel.org>