crypto: msm: ota: check zero length request

Check zero length request.

Change-Id: I53f26d3df813c3dbd07258e14557cccb028a606f
Acked-by: Chemin Hsieh <cheminh@qti.qualcomm.com>
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: Venkatesh Yadav Abbarapu <quicvenkat@codeaurora.org>