net: rmnet_data: Always try to linearize when UL aggregation is on

Skipping UL aggregation if the packet was linear was causing out
of order packets. If linearization fails, pass up the packet as is.
Also skip padding if using version 3 or v4 when using UL aggregation.

CRs-Fixed: 2141234
Change-Id: I711668ecf2a3e6807f2270b4b107f4a2a3d21654
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>