egl/dri2: Fix memory leak.

Fixes resource leak defect reported by Coverity.

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Brian Paul <brianp@vmware.com>

src/egl/drivers/dri2/egl_dri2.c

@@ -768,6 +768,7 @@ dri2_create_context(_EGLDriver *drv, _EGLDisplay *disp, _EGLConfig *conf,
       break;
    default:
       _eglError(EGL_BAD_PARAMETER, "eglCreateContext");
+      free(dri2_ctx);
       return NULL;
    }