msm: ipa: cache status src_pipe before invoking RX callback

The RX callback can result in forwarding the skb to RNDIS netdev
whose RNDIS header push will corrupt the status element.

Change-Id: Id48e3f8352a2fd5d549491ebc69db58c60fc429c
Signed-off-by: Ravi Gummadidala <rgummadi@codeaurora.org>