ethtool: pse-pd: Fix double word in comments

Remove the repeated word "for" in comments.

Signed-off-by: Bo Liu <[email protected]>
Reviewed-by: Oleksij Rempel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Bo Liu

net/ethtool/pse-pd.c

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 //
-// ethtool interface for for Ethernet PSE (Power Sourcing Equipment)
+// ethtool interface for Ethernet PSE (Power Sourcing Equipment)
 // and PD (Powered Device)
 //
 // Copyright (c) 2022 Pengutronix, Oleksij Rempel <[email protected]>