IPA HAL: fix the upstream down issue

When upstream interface went down but
tethered interface still up, send "NULL"
upstream iface name to IPACM to clean up
previous up upstream interface.

CRs-fixed:2125887
Bug:67396342
Test: compile

Change-Id: Ic586072721f9a053126ae0e6a54a00c196632a35
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>
Signed-off-by: Niranjan Pendharkar <npendhar@codeaurora.org>
(cherry picked from commit 4b09d0b7556d2bbd8da714a9a8b51ebd6cf5a061)
1 file changed
tree: fd5a8cb2167e871fe60edd79dcc915f235d44602
  1. msm8998/
  2. Android.mk