Marlin: Slight cleanup to Marlin_main.cpp

Marlin/Marlin_main.cpp

   #define KEEPALIVE_STATE(n) ;
 #endif // HOST_KEEPALIVE_FEATURE
 
-#define DEFINE_PGM_READ_ANY(type, reader)       \
-  static inline type pgm_read_any(const type *p)  \
-  { return pgm_read_##reader##_near(p); }
-
-DEFINE_PGM_READ_ANY(float,       float)
-DEFINE_PGM_READ_ANY(signed char, byte)
+static inline float pgm_read_any(const float *p) { return pgm_read_float_near(p); }
+static inline signed char pgm_read_any(const signed char *p) { return pgm_read_byte_near(p); }
 
 #define XYZ_CONSTS_FROM_CONFIG(type, array, CONFIG) \
-  static const PROGMEM type array##_P[XYZ] =        \
-      { X_##CONFIG, Y_##CONFIG, Z_##CONFIG };     \
-  static inline type array(int axis)          \
-  { return pgm_read_any(&array##_P[axis]); }
+  static const PROGMEM type array##_P[XYZ] = { X_##CONFIG, Y_##CONFIG, Z_##CONFIG }; \
+  static inline type array(AxisEnum axis) { return pgm_read_any(&array##_P[axis]); }
 
 XYZ_CONSTS_FROM_CONFIG(float, base_min_pos,   MIN_POS)
 XYZ_CONSTS_FROM_CONFIG(float, base_max_pos,   MAX_POS)
     cmd[sizeof(cmd) - 1] = '\0';
     while ((c = cmd[i]) && c != '\n') i++; // find the end of this gcode command
     cmd[i] = '\0';
-    if (shove_and_echo_command(cmd)) {     // success?
-      if (c)                               // newline char?
-        injected_commands_P += i + 1;      // advance to the next command
-      else
-        injected_commands_P = NULL;        // nul char? no more commands
-    }
+    if (shove_and_echo_command(cmd))       // success?
+      injected_commands_P = c ? injected_commands_P + i + 1 : NULL; // next command or done
   }
   return (injected_commands_P != NULL);    // return whether any more remain
 }