Reduce verbosity for QT_XCB_GL_INTEGRATION=none

When QT_XCB_GL_INTEGRATION=none we were printing:

1) qt.xcb.glintegration: QT_XCB_GL_INTEGRATION is set to "none"
2) qt.xcb.glintegration: Choosing xcb gl-integration based on following priority ()
3) qt.xcb.glintegration: Failed to create xcb gl-integration

Omit line 2 (useless) and line 3 (misleading).

Change-Id: If5e65a5bc8cc4a1fa97858049a26aac9a9535950
Reviewed-by: Shawn Rutledge <shawn.rutledge@theqtcompany.com>