This episode illustrates how an overused warning can train people to
ignore that warning, which winds up hiding bugs.
The warning
drivers/net/natsemi.c: In function ‘natsemi_remove1’:
drivers/net/natsemi.c:3222: warning: ignoring return value of
‘device_create_file’, declared with attribute warn_unused_result
is oft-ignored, even though at close inspection one notices this occurs
in the /remove/ function, not normally where creation occurs. A quick
s/create/remove/ and we are fixed, with the warning gone.