drm/msm: Remove redundant check for 'submit'

Rectify the below smatch warning:
drivers/gpu/drm/msm/msm_gem_submit.c:963 msm_ioctl_gem_submit() warn:
variable dereferenced before check 'submit'

'submit' is normally error pointer or valid, so remove its NULL
initializer as it's confusing and also remove a redundant check for it's
value.

Signed-off-by: Aashish Sharma <shraash@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/506653/
Link: https://lore.kernel.org/r/20221011075519.3111928-1-shraash@google.com
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/msm_gem_submit.c

@@ -706,7 +706,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	struct msm_drm_private *priv = dev->dev_private;
 	struct drm_msm_gem_submit *args = data;
 	struct msm_file_private *ctx = file->driver_priv;
-	struct msm_gem_submit *submit = NULL;
+	struct msm_gem_submit *submit;
 	struct msm_gpu *gpu = priv->gpu;
 	struct msm_gpu_submitqueue *queue;
 	struct msm_ringbuffer *ring;
@@ -946,8 +946,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 		put_unused_fd(out_fence_fd);
 	mutex_unlock(&queue->lock);
 out_post_unlock:
-	if (submit)
-		msm_gem_submit_put(submit);
+	msm_gem_submit_put(submit);
 	if (!IS_ERR_OR_NULL(post_deps)) {
 		for (i = 0; i < args->nr_out_syncobjs; ++i) {
 			kfree(post_deps[i].chain);