Fixed to draw texture when loadTexture() is called at first time

SW renderer of Stagefright reaches loadTexture() to draw image.
The first time loadTexture() is called, it just initializes OGL
texture, then returns. Thus, the first time call doesn't draw.
This patch fixes to move on to draw stage after the initialization.

Change-Id: I3ec1ad68fb8d376a4ad7aefded1c18a002d175c4