Txn IDs created up to INT_MAX cause overflow while storing
the IDs in u16 type supported by QMI header.

Limit the txn IDs max value to U16_MAX to avoid overflow.
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>