[PATCH v4] raw/ntb: clear all valid DB bits when DB init

[Thomas Monjalon]

> > Before registering the doorbell interrupt handler callback function,
> > all the valid doorbell bits within the NTB private data struct should
> > be cleared to avoid the confusion of the handshake timing sequence
> > diagram when setting up the NTB connection in back-to-back mode.
> > 
> > Fixes: 62012a76811e ("raw/ntb: add handshake process")
> > Cc: stable at dpdk.org
> > 
> > v2: fix typo
> > v3: fix coding style issue
> > v4: add ops check before calling it

The changelog should be below line of ---

> > Signed-off-by: Junfeng Guo <junfeng.guo at intel.com>
> Acked-by: Jingjing Wu <jingjing.wu at intel.com>

Applied, thanks.