msm: camera: Fix improper subdev find functionality

There is a bug in msm_sd_find function in which if the
subdev is not present, the last entry will be sent to
the caller. Added the code to fix this.

Change-Id: I250d0383f5b6c954d301ce0caa6a1f7a9adbf267
Signed-off-by: Sunid Wilson <sunidw@codeaurora.org>