Fixing minor typo that propagates from copy/paste.

generators/arduino/io.js

@@ -171,7 +171,7 @@ Blockly.Arduino['io_analogread'] = function(block) {
   if (pinKey in Blockly.Arduino.pins_) {
     if (Blockly.Arduino.pins_[pinKey] != pinType) {
       block.setWarningText(
-          'Pin alredy used as ' + Blockly.Arduino.pins_[pinKey]);
+          'Pin already used as ' + Blockly.Arduino.pins_[pinKey]);
     } else {
       block.setWarningText(null);
     }

generators/arduino/servo.js

@@ -40,7 +40,7 @@ Blockly.Arduino['servo_write'] = function(block) {
   // If the IO has been configured already set a block warning for the user
   if (pinKey in Blockly.Arduino.pins_) {
      if (Blockly.Arduino.pins_[pinKey] != pinType) {
-       block.setWarningText('Pin alredy used as ' + Blockly.Arduino.pins_[pinKey]);
+       block.setWarningText('Pin already used as ' + Blockly.Arduino.pins_[pinKey]);
      } else {
        block.setWarningText(null);
      }
@@ -77,7 +77,7 @@ Blockly.Arduino['servo_read'] = function(block) {
   // If the IO has been configured already set a block warning for the user
   if (pinKey in Blockly.Arduino.pins_) {
      if (Blockly.Arduino.pins_[pinKey] != pinType) {
-       block.setWarningText('Pin alredy used as ' + Blockly.Arduino.pins_[pinKey]);
+       block.setWarningText('Pin already used as ' + Blockly.Arduino.pins_[pinKey]);
      } else {
        block.setWarningText(null);
      }

generators/arduino/spi.js

@@ -97,7 +97,7 @@ Blockly.Arduino['spi_transfer'] = function(block) {
     // If the IO has been configured already set a warning for the user
     if (spiSs in Blockly.Arduino.pins_) {
       if (Blockly.Arduino.pins_[spiSs] != pinType) {
-        warningText = warningText + 'Pin alredy used as ' +
+        warningText = warningText + 'Pin already used as ' +
             Blockly.Arduino.pins_[spiSs];
       }
     } else {