use enabled macro for mapper setting

Marlin/ultralcd.cpp

@@ -2469,10 +2469,10 @@ void lcd_init() {
 int lcd_strlen(const char* s) {
   int i = 0, j = 0;
   while (s[i]) {
-    #ifdef MAPPER_NON
+    #if ENABLED(MAPPER_NON)
       j++;
     #else
-      if ((s[i] & 0xc0) != 0x80) j++;
+      if ((s[i] & 0xC0u) != 0x80u) j++;
     #endif
     i++;
   }
@@ -2482,10 +2482,10 @@ int lcd_strlen(const char* s) {
 int lcd_strlen_P(const char* s) {
   int j = 0;
   while (pgm_read_byte(s)) {
-    #ifdef MAPPER_NON
+    #if ENABLED(MAPPER_NON)
       j++;
     #else
-      if ((pgm_read_byte(s) & 0xc0) != 0x80) j++;
+      if ((pgm_read_byte(s) & 0xC0u) != 0x80u) j++;
     #endif
     s++;
   }