amd-xgbe: Don't overwrite SFP PHY mod_absent settings

amd-xgbe: Don't overwrite SFP PHY mod_absent settings

BugLink: http://bugs.launchpad.net/bugs/1675032
[ Upstream commit 2697ea5a859b83ca49511dcfd98daf42584eb3cf ]

If an SFP module is not present, xgbe_phy_sfp_phy_settings() should
return after applying the default settings. Currently there is no return
statement and the default settings are overwritten.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>