drm/exynos: g2d: make ioctls more robust
drm/exynos: g2d: make ioctls more robust

Both exynos_g2d_set_cmdlist_ioctl and exynos_g2d_exec_ioctl don't check
if the G2D was succesfully probe. If that is not the case, then g2d_priv
is just NULL and extracting 'dev' from it in the next step  is going to
produce a kernel oops.

Add proper checks and return ENODEV if the G2D is not available.

Signed-off-by: Tobias Jakobi <4c4bdab7e8565a5c263c93a14c8947afdc7cdad5@math.uni-bielefeld.de>
Signed-off-by: INki Dae <bae4a7a27bbc965064e97edd6e179ac4979db440@samsung.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs