setterm: avoid restoring flags from uninitialized memory

setterm: avoid restoring flags from uninitialized memory

Depending on the used compiler and flags, previously either F_SETFL was called
with 0 or with a random value. Never with the intended previous flags.

[kzak@redhat.com: - tiny coding style change]

Signed-off-by: Chris Hofstaedtler <zeha@debian.org>
Tested-by: Emanuele Rocca <ema@debian.org>
Signed-off-by: Karel Zak <kzak@redhat.com>
Gbp-Pq: Topic upstream
Gbp-Pq: Name setterm-resize-uninit-flags.patch