wifi: iwlwifi: remove WARN from read_mem32()

There's no reason to warn here, it's not an internal consistency
issue, we even use this to check if the device is dead, and if it
read_mem() returns an error that's either because grab NIC access
or memory allocation failed, both of which are already noisy.

Just remove the warning entirely.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230816104355.5f4e80eb63cc.Iffd88f63f95575f28e503da13b473724e3341aee@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>