[PATCH 01/61] Coccinelle: Prefer IS_ERR_OR_NULL over manual NULL check

[Markus Elfring]

…
> +// Confidence: High

Some contributors presented discerning comments for this change approach.
Thus I became also curious how much they can eventually be taken better into account
by the means of the semantic patch language (Coccinelle software).

…
+ at p1 depends on patch@
+expression E;
+@@
+(
> +-	E != NULL && !IS_ERR(E)
> ++	!IS_ERR_OR_NULL(E)
> +|
> +-	E == NULL || IS_ERR(E)
> ++	IS_ERR_OR_NULL(E)
> +|
> +-	!IS_ERR(E) && E != NULL
> ++	!IS_ERR_OR_NULL(E)
> +|
> +-	IS_ERR(E) || E == NULL
> ++	IS_ERR_OR_NULL(E)
> +)

Several detected expressions should refer to return values from function calls.
https://en.wikipedia.org/wiki/Return_statement

* Do any development challenges hinder still the determination of corresponding
  failure predicates?

* How will interests evolve to improve data processing any further for such
  use cases?


Regards,
Markus