net: phylink: rearrange phylink_parse_mode()

Of the two users of phylink_config->ovr_an_inband, both manually check
for a fixed link before setting this flag (or clearing it if they find
a fixed link.) This is unnecessary complication.

Rearrange phylink_parse_mode() a little so we can change how
phylink_config->ovr_an_inband works. This will allow the flag to be
tested before checking for the fixed link properties in the next patch.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Link: https://lore.kernel.org/r/E1sCJMl-00Ecqp-K0@rmk-PC.armlinux.org.uk


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