staging: drm/omap: Fix usage of IS_ERR_OR_NULL and PTR_ERR
staging: drm/omap: Fix usage of IS_ERR_OR_NULL and PTR_ERR

Return PTR_ERR(-ENOMEM) if dmm_txn_init cannot allocate a
refill engine.

Signed-off-by: Andy Gross <4ba87047449f5700e8758e3b1af36e94376c2fff@ti.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs