If potentially no valid element is found, 'priv_rx' would contain an
invalid pointer past the iterator loop. To ensure 'priv_rx' is always
valid, we only set it if the correct element was found. That allows
adding a WARN_ON() in case the code works incorrectly, exposing
currently undetectable potential bugs.
Additionally, Linus proposed to avoid any use of the list iterator
variable after the loop, in the attempt to move the list iterator
variable declaration into the macro to avoid any potential misuse after
the loop [1].
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@xxxxxxxxxxxxxx/ [1]
Signed-off-by: Jakob Koschel <jkl820.git@xxxxxxxxx>