input: synaptics_fw_update: Rectify the package_id parsing

Rectify the package id parsing which aborts firmware upgradation
due to package id mismatch.

CRs-Fixed: 574411
Change-Id: Ib047b8824e270c4ab57c7524c74dfb4dac9378f1
Signed-off-by: Sarada Prasanna Garnayak <c_sgarna@codeaurora.org>