input: synaptics_fw_update: fix print statements

%zu is the correct printk format specifier when printing size_t types.

Update printks to use %zu for size_t type variables.

This patch is propagated from the msm-3.10 kernel
(commit: 1fd3845651a5d9451ac7568cb8bdba98bb8554ab
input: synaptics_fw_update:  fix print statements)

Change-Id: Ie556fd14293ecd36143353e575fd5ef22fab20f7
Signed-off-by: Himanshu Aggarwal <haggarwa@codeaurora.org>