amd-xgbe: do not double read link status

amd-xgbe: do not double read link status

The link status is latched low so that momentary link drops
can be detected. Always double-reading the status defeats this
design feature. Only double read if link was already down

This prevents unnecessary duplicate readings of the link status.

Fixes: 4f3b20bfbb75 ("amd-xgbe: add support for rx-adaptation")
Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250701065016.4140707-1-Raju.Rangoju@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>