net: lan743x: Simplify comparison

Simplify comparison, no functional changes.

Cc: Bryan Whitehead <bryan.whitehead@microchip.com>
Cc: UNGLinuxDriver@microchip.com
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Moritz Fischer <moritzf@google.com>
Link: https://lore.kernel.org/r/20230627035432.1296760-1-moritzf@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>