checkpatch: remove custom max line length

I noticed that the recent trend is to avoid coding style differences
between subtrees, e.g. commit 82b8000c28b5 ("net: drop special comment
style") in the kernel repository.

I then wonder if this netdev specific limit still makes sense today. I
didn't find anything about it in the kernel documentation, nor in the
commit introducing it here in this repo: commit 950c7e3 ("bring back 80
char max len").

On MPTCP side, the preferred limit on the length of a single line is 80
columns. But when this improves the readability, some lines are a bit
over 80 chars, e.g. for the parameters of a function, comments next to
fields of a structure, etc. I don't think we abuse of this, but we
regularly have warnings on Patchwork that we are over the 80 chars
limit. I don't think we ever had any comments about that, that's why we
continued to use the default limit, while still keeping most of the code
under the 80 chars limit.

Then is it fine to drop this limit, and use the default one? Or should
we really try to limit the length to 80 chars and the documentation
needs to be updated instead?

Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>

tests/patch/checkpatch/checkpatch.sh

@@ -13,7 +13,7 @@ CAMELCASE
 
 tmpfile=$(mktemp)
 
-./scripts/checkpatch.pl --strict --max-line-length=80 --ignore=$IGNORED -g HEAD | tee $tmpfile
+./scripts/checkpatch.pl --strict --ignore=$IGNORED -g HEAD | tee $tmpfile
 
 grep 'total: 0 errors, 0 warnings, 0 checks' $tmpfile
 ret=$?