Apply #pragma once, misc cleanup (#12322)

* Apply #pragma once in headers
* Adjust some thermistors formatting
* Misc cleanup and formatting

Marlin/src/feature/bedlevel/abl/abl.h

@@ -19,9 +19,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-
-#ifndef __ABL_H__
-#define __ABL_H__
+#pragma once
 
 #include "../../../inc/MarlinConfig.h"
 
@@ -47,5 +45,3 @@
   #endif
 
 #endif // AUTO_BED_LEVELING_BILINEAR
-
-#endif // __ABL_H__

Marlin/src/feature/bedlevel/bedlevel.h

@@ -19,9 +19,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-
-#ifndef __BEDLEVEL_H__
-#define __BEDLEVEL_H__
+#pragma once
 
 #include "../../inc/MarlinConfigPre.h"
 
@@ -85,5 +83,3 @@ void reset_bed_level();
 #elif HAS_ABL
   #include "abl/abl.h"
 #endif
-
-#endif // __BEDLEVEL_H__

Marlin/src/feature/bedlevel/mbl/mesh_bed_leveling.h

@@ -19,9 +19,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-
-#ifndef _MESH_BED_LEVELING_H_
-#define _MESH_BED_LEVELING_H_
+#pragma once
 
 #include "../../../inc/MarlinConfig.h"
 
@@ -120,5 +118,3 @@ public:
 };
 
 extern mesh_bed_leveling mbl;
-
-#endif // _MESH_BED_LEVELING_H_

Marlin/src/feature/bedlevel/ubl/ubl.h

@@ -19,9 +19,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-
-#ifndef UNIFIED_BED_LEVELING_H
-#define UNIFIED_BED_LEVELING_H
+#pragma once
 
 //#define UBL_DEVEL_DEBUGGING
 
@@ -372,5 +370,3 @@ class unified_bed_leveling {
 }; // class unified_bed_leveling
 
 extern unified_bed_leveling ubl;
-
-#endif // UNIFIED_BED_LEVELING_H