media: dib7000p: Remove dead code

Clang warns that 'interleaving' is assigned to itself in this function.

drivers/media/dvb-frontends/dib7000p.c:1874:15: warning: explicitly
assigning value of variable of type 'int' to itself [-Wself-assign]
        interleaving = interleaving;
        ~~~~~~~~~~~~ ^ ~~~~~~~~~~~~
1 warning generated.

Just remove the self-assign and leave existing code in place for now.

Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>