Revert "drm/omapdrm: cleanup: drm_modeset_lock_all() --> DRM_MODESET_LOCK_ALL_BEGIN()"

This reverts commit 6067fddc1a4fdf155787ab6182c192e4b360b73c.

This patchset breaks on intel platforms and was previously NACK'd by
Ville.

Cc: Ville Syrjälä <[e-mail]>
Cc: Fernando Ramos <[e-mail]>
Acked-by: Ville Syrjälä <[e-mail]>
Signed-off-by: Sean Paul <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/omapdrm/omap_fb.c

···
 #include <drm/drm_modeset_helper.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_framebuffer_helper.h>
-#include <drm/drm_drv.h>
 
 #include "omap_dmm_tiler.h"
 #include "omap_drv.h"
···
 				  unsigned num_clips)
 {
 	struct drm_crtc *crtc;
-	struct drm_modeset_acquire_ctx ctx;
-	int ret;
 
-	DRM_MODESET_LOCK_ALL_BEGIN(fb->dev, ctx, 0, ret);
+	drm_modeset_lock_all(fb->dev);
 
 	drm_for_each_crtc(crtc, fb->dev)
 		omap_crtc_flush(crtc);
 
-	DRM_MODESET_LOCK_ALL_END(fb->dev, ctx, ret);
+	drm_modeset_unlock_all(fb->dev);
 
-	return ret;
+	return 0;
 }
 
 static const struct drm_framebuffer_funcs omap_framebuffer_funcs = {