rmnet_data: skip padding count for non linear skbs

This patch addresses two issues
a) The original GSO patch had a condition to check
   for padding on a non linear skb and the egress
	 device, but the device name was incorrect leading
	 to the check always failing. This patch eliminates
	 the need for the check completely.

b) It is possible that the last frag in a GSO frame
   would not be size aligned to a word boundary. In
	 this and all cases involving a non linear skb
	 frame we should skip padding. The driver can
	 expect a non linear packet when Scatter Gather
	 feature is enabled on the device. This patch
	 does just that.

Change-Id: Ifea5b1ae26b154bb047044e4bc3ad579d0da7f6d
CRs-fixed: 990751
Acked-by: Ashwanth Goli <ashwanth@qti.qualcomm.com>
Signed-off-by: Sharat Masetty <smasetty@codeaurora.org>