tty: goldfish: drop unneeded temporary variables

We can pass 'buf' directly to goldfish_tty_rw() using simple (unsigned
long) cast. There is no need to obfuscate the code by another variable
with double casts.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231121092258.9334-9-jirislaby@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>