drm/exynos: remove call to drm_gem_free_mmap_offset()
drm/exynos: remove call to drm_gem_free_mmap_offset()

The drm_gem_object_release() function already performs this cleanup,
so there is no reason to do it explicitly.

Signed-off-by: Joonyoung Shim <b2207686f8c5343cf0f505ae1d5720ecb0c3202a@samsung.com>
Signed-off-by: Inki Dae <bae4a7a27bbc965064e97edd6e179ac4979db440@samsung.com>

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