Simplify counting of printable characters

Marlin/macros.h

@@ -127,7 +127,6 @@
 #define DECIMAL(a) (NUMERIC(a) || a == '.')
 #define NUMERIC_SIGNED(a) (NUMERIC(a) || (a) == '-' || (a) == '+')
 #define DECIMAL_SIGNED(a) (DECIMAL(a) || (a) == '-' || (a) == '+')
-#define PRINTABLE(C) (((C) & 0xC0u) != 0x80u)
 #define COUNT(a) (sizeof(a)/sizeof(*a))
 #define ZERO(a) memset(a,0,sizeof(a))
 #define COPY(a,b) memcpy(a,b,min(sizeof(a),sizeof(b)))

Marlin/ultralcd.cpp

@@ -3885,11 +3885,7 @@ void lcd_init() {
 int lcd_strlen(const char* s) {
   int i = 0, j = 0;
   while (s[i]) {
-    #if ENABLED(MAPPER_NON)
-      j++;
-    #else
     if (PRINTABLE(s[i])) j++;
-    #endif
     i++;
   }
   return j;
@@ -3898,11 +3894,7 @@ int lcd_strlen(const char* s) {
 int lcd_strlen_P(const char* s) {
   int j = 0;
   while (pgm_read_byte(s)) {
-    #if ENABLED(MAPPER_NON)
-      j++;
-    #else
     if (PRINTABLE(pgm_read_byte(s))) j++;
-    #endif
     s++;
   }
   return j;
@@ -4167,11 +4159,7 @@ void lcd_update() {
   void set_utf_strlen(char* s, uint8_t n) {
     uint8_t i = 0, j = 0;
     while (s[i] && (j < n)) {
-      #if ENABLED(MAPPER_NON)
-        j++;
-      #else
       if (PRINTABLE(s[i])) j++;
-      #endif
       i++;
     }
     while (j++ < n) s[i++] = ' ';

Marlin/utf_mapper.h

@@ -144,6 +144,8 @@
   #endif // DISPLAY_CHARSET_HD44780
 #endif // SIMULATE_ROMFONT
 
+#define PRINTABLE(C) (((C) & 0xC0u) != 0x80u)
+
 #if ENABLED(MAPPER_C2C3)
 
   char charset_mapper(const char c) {
@@ -466,6 +468,9 @@
 
   #define MAPPER_NON
 
+  #undef PRINTABLE
+  #define PRINTABLE(C) true
+
   char charset_mapper(const char c) {
     HARDWARE_CHAR_OUT(c);
     return 1;