TabBarItem: Removed unnecessary render call

Issue
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The `render` call on the `TabBarItem` button causes issues when the button is customized to contain components that are floating; these floating components lose their owner because they are not re-generated when render is called.

Fix
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The `render` call is unnecessary as `applyStyle` already applies the width changes on the node.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>