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>
diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index d10bdf0..0ffbc68 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -768,6 +768,7 @@
       break;
    default:
       _eglError(EGL_BAD_PARAMETER, "eglCreateContext");
+      free(dri2_ctx);
       return NULL;
    }