Prevent heap overflow in uvc driver

The size of uvc_control_mapping is user controlled leading to a
potential heap overflow in the uvc driver. This adds a check to verify
the user provided size fits within the bounds of the defined buffer
size.

Bug: 33300353
Change-Id: If29c1b396633b6137966a12e38f6fd1841b045bd
Signed-off-by: Robb Glasser <rglasser@google.com>