link-hint--apply: Attempt to improve the condition-case madness

[stepnem]

There is func-arity' (since Emacs 26.1; there was only subr-arity' before that), but instead of trying to parse and deal with all possible arity implications, simplify the logic to the following:

• if ARGS is a list, leave it alone and use `apply'
• if it is a non-list, wrap it in a list and use `apply'
• instead of catching all errors and breaking in all kinds of unexpected ways (e.g. when FUNC signals an unrelated but legitimate error), handle only `wrong-number-of-arguments', for cases where FUNC doesn't want any

[noctuid]

Catching the specific error is better. This wouldn't work for a function that takes a list as a single argument though.