Fix a couple of doubled semicolons

Marlin/ultralcd_implementation_hitachi_HD44780.h

@@ -396,7 +396,7 @@ char lcd_printPGM(const char* str) {
 }
 
 char lcd_print(char* str) {
-  char c, n = 0;;
+  char c, n = 0;
   unsigned char i = 0;
   while ((c = str[i++])) n += charset_mapper(c);
   return n;