[qca-nss-drv] Fix Max Buffer size supported for FSM9010

Initialize the Max Buffer size variable before enabling
NSS interrupt. This possibly might create a race condition
and empty buffers of zero size will be passed to NSS.

Change-Id: I0a55751cddff63eaabc20980aa3782cd3b6d2139
Signed-off-by: Arunkumar T <athand@codeaurora.org>
3 files changed