msm: ipa: fix compilation issues on sdxpoorwills

The current code has a problem compiling on ecm_ipa.c. To fix this issue,
remove parantheses from a macro causing compile error, remove
prototype for unused function, and use netif_trans_update instead of
the legacy net->trans_start.

Change-Id: I2d08772c762c9ba81ecf13d857b18f837cbf4195
CRs-Fixed: 2044228
Signed-off-by: Michael Adisumarta <madisuma@codeaurora.org>