staging: wimax: Fix some coding style problem

This fixes checkpatch error "open brace '{' following struct go on
the same line" in file drivers/staging/wimax/i2400m/rx.c .

Signed-off-by: Hemansh Agnihotri <hemanshagnihotri27@gmail.com>
Link: https://lore.kernel.org/r/20210212033256.2116-1-hemanshagnihotri27@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>