net: fddi: skfp: Remove unused function

Clang warns when a variable is assigned to itself.

drivers/net/fddi/skfp/pcmplc.c:1257:6: warning: explicitly assigning
value of variable of type 'int' to itself [-Wself-assign]
        phy = phy ; on_off = on_off ;
        ~~~ ^ ~~~
drivers/net/fddi/skfp/pcmplc.c:1257:21: warning: explicitly assigning
value of variable of type 'int' to itself [-Wself-assign]
        phy = phy ; on_off = on_off ;
                    ~~~~~~ ^ ~~~~~~
2 warnings generated.

Turns out this entire function doesn't actually do anything since
SK_UNUSED is just casting the pointer to void. Remove it to silence
this Clang warning.

Link: https://github.com/ClangBuiltLinux/linux/issues/128


Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>