msm: camera: isp: Fix incorrect compat pointer conversion.

The conversion done in compat ioctl is incorrect. V4L2 core takes care
for it, thus doing this second time leads to obtaining incorrect
address.

Change-Id: I2e1553aa4d64787e31a772a3af428a2a99e54676
Signed-off-by: Petar Sivenov <psiven@codeaurora.org>