USB: serial: digi_acceleport: remove in_interrupt() usage

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated or the context be conveyed in an argument passed by the
caller, which usually knows the context.

The debug printk() in digi_write() prints in_interrupt() as context
information. This information is imprecise as it does not distinguish
between hard-IRQ or disabled bottom half and it does not consider
disabled interrupts or preemption. It is not really helpful.

Remove the in_interrupt() printout.

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20201026140313.dpg3hkhkje2os4hw@linutronix.de


[ johan: amend commit message ]
Signed-off-by: Johan Hovold <johan@kernel.org>