net: stmmac: clean up stmmac_reset()

net: stmmac: clean up stmmac_reset()

stmmac_reset() takes the stmmac_priv and an ioaddr. It has one call
site, which passes the priv pointer, and dereferences priv for the
ioaddr.

stmmac_reset() then checks whether priv is NULL. If it was, the caller
would have oopsed. Remove the checks for NULL, and move the dereference
for ioaddr into stmmac_reset().

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1vImWF-0000000DrIr-1fmn@rmk-PC.armlinux.org.uk
Signed-off-by: Paolo Abeni <pabeni@redhat.com>