msm: qmi: Subtract the wire size of an array length appropriately

If an element is an array of structure and if that element has type and
length information present in the message's QMI wire format, then subtract
the wire size of the array length from the length information while
decoding that element.

Change-Id: If460820b42894dd8611e67780aef5bd1722b3ef9
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>