Fix compilation warnings, errors (#14704)

Marlin/src/core/language.h

@@ -37,7 +37,7 @@
 
 // NOTE: IF YOU CHANGE LANGUAGE FILES OR MERGE A FILE WITH CHANGES
 //
-//   ==> ALWAYS TRY TO COMPILE MARLIN WITH/WITHOUT "ULTIPANEL" / "ULTRALCD" / "SDSUPPORT" #define IN "Configuration.h"
+//   ==> ALWAYS TRY TO COMPILE MARLIN WITH/WITHOUT "ULTIPANEL" / "ULTRA_LCD" / "SDSUPPORT" #define IN "Configuration.h"
 //   ==> ALSO TRY ALL AVAILABLE LANGUAGE OPTIONS
 // See also http://marlinfw.org/docs/development/lcd_language.html