soc: qcom: smem: byte swap values properly

Two places report an error when a partition header is found to
not contain the right canary value.  The error messages do not
properly byte swap the host ids.  Fix this, and adjust the format
specificier to match the 16-bit unsigned data type.

Move the error handling for a bad canary value to the end of
qcom_smem_alloc_private().  This avoids some long lines, and
reduces the distraction of handling this unexpected problem.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>