Fixed an incorrect word in the blurTextInput() documentation.

Summary:
In `TextInputState`'s `blurTextInput()` documentation, the parameter description`id of the text field to focus` should be `id of the text field to unfocus`, since this is `blurTextInput` and not `focusTextInput`.

N/A (just documentation fix).
Closes #14367

Differential Revision: D5200263

Pulled By: shergin

fbshipit-source-id: b3e9ab60e555ad9050474b59a728761180618190

Author: jstheoriginal

Libraries/Components/TextInput/TextInputState.js

@@ -53,7 +53,7 @@ var TextInputState = {
   },
 
   /**
-   * @param {number} textFieldID id of the text field to focus
+   * @param {number} textFieldID id of the text field to unfocus
    * Unfocuses the specified text field
    * noop if it wasn't focused
    */