drm: Spelling fixes

Minor spelling fix for 'monster' and replace 'on' with 'own' in
comments.

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171101140436.2743-1-Liviu.Dudau@arm.com

drivers/gpu/drm/drm_atomic.c

@@ -1808,7 +1808,7 @@ int drm_atomic_debugfs_init(struct drm_minor *minor)
 #endif
 
 /*
- * The big monstor ioctl
+ * The big monster ioctl
  */
 
 static struct drm_pending_vblank_event *create_vblank_event(

drivers/gpu/drm/drm_mm.c

@@ -92,7 +92,7 @@
  * some basic allocator dumpers for debugging.
  *
  * Note that this range allocator is not thread-safe, drivers need to protect
- * modifications with their on locking. The idea behind this is that for a full
+ * modifications with their own locking. The idea behind this is that for a full
  * memory manager additional data needs to be protected anyway, hence internal
  * locking would be fully redundant.
  */