staging: bcm2835-camera: fix error handling in init

The unwinding here isn't right.  We don't free gdev[0] and instead
free 1 step past what was allocated.  Also we can't allocate "dev" then
we should unwind instead of returning directly.

Fixes: 7b3ad5ab ("staging: Import the BCM2835 MMAL-based V4L2 camera driver.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: walter harms <wharms@bfs.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>