linux_spi.c: Drop some unnecessary initialisations and checks

In previous patches 52283, 52284, 52285 there were some unresolved
comments left, resolving [and replying to] all of that here.

TEST=builds and ninja test from 51487
BUG=b:185191942

Change-Id: I27a718b515fc474f63b3e61be58a6f9302527559
Signed-off-by: Anastasia Klimchuk <aklm@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/52492
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
1 file changed