Hi Anteru,
It is a known issue and issue has been raised to OpenGL driver team. It is supposed to fix in next release of driver.
This is because, the sharing seems to be broken if context version is 4.x.
Alternatively for the time being, you can replace glXCreateContextAttribsARB() function with glXCreateContext() to create GL context. The later one will create latest GL context, as supported by installed driver (as in this case 4.4 version) and sample should work without fail.
Thanks!