power: qpnp-linear-charger: Fix array index issue.

The array index can go out of bound, so fixing it.

Change-Id: I058060b33221654f797284d38e88061058b5e0f1
Signed-off-by: Venkatesh Yadav Abbarapu <quicvenkat@codeaurora.org>
Signed-off-by: arusha goyal <arushag@codeaurora.org>