[qca-nss-drv] Fix potential list corruption in nss_qdisc.c

The newly added root hash in nss_qdisc was not properly lock protected.
The following fix protects the list using spinlocks.

CRs-Fixed: 684134
Change-Id: I8ef9a89083f93844cea37bca1bb92cdb9c91fd3e
Signed-off-by: Sakthi Vignesh Radhakrishnan <sradhakr@codeaurora.org>
1 file changed