🩹 Fix strtof interpreting a hex value

Bug introduced in #21532

Marlin/src/gcode/parser.h

@@ -256,12 +256,12 @@ public:
 
   // Float removes 'E' to prevent scientific notation interpretation
   static float value_float() {
-    if (value_ptr) {
+    if (!value_ptr) return 0;
     char *e = value_ptr;
     for (;;) {
       const char c = *e;
       if (c == '\0' || c == ' ') break;
-        if (c == 'E' || c == 'e') {
+      if (c == 'E' || c == 'e' || c == 'X' || c == 'x') {
         *e = '\0';
         const float ret = strtof(value_ptr, nullptr);
         *e = c;
@@ -271,8 +271,6 @@ public:
     }
     return strtof(value_ptr, nullptr);
   }
-    return 0;
-  }
 
   // Code value as a long or ulong
   static int32_t value_long() { return value_ptr ? strtol(value_ptr, nullptr, 10) : 0L; }