net: ravb: Fix possible hang if RIS2_QFF1 happen

[ Upstream commit f3c07758 ]

Since this driver enables the interrupt by RIC2_QFE1, this driver
should clear the interrupt flag if it happens. Otherwise, the interrupt
causes to hang the system.

Note that this also fix a minor coding style (a comment indentation)
around the fixed code.

Fixes: c156633f

 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>