[BUG][TUTORIAL] Tutorial for quantization need update

[Robeast]

Dear community,
I've noticed that the stock tutorial for quantization fails if the following call is changed from local scales to global scales:

...
mod = quantize(mod, params, data_aware=True) # -> fails with data_aware=False 
...

ValueError: Unknown calibrate mode global

The fix is straight forward:

-         with relay.quantize.qconfig(calibrate_mode='global', global_scale=8.0):
---
+        with relay.quantize.qconfig(calibrate_mode='global_scale', global_scale=8.0):

I would like to kindly ask @vinx13 to update the tutorial. Thank you very much in advance & best regards!

[tqchen]

feel free to send a PR to fix this

[Robeast]

@tqchen I'm extremely ashamed to say this, but due to company policy I'm not allowed to contribute to anything other than company code bases. Especially shameful since it's only 1 string change... :( I'm really sorry.

[tqchen]

no problem, thanks @Robeast for reporting the problem :)

[Robeast]

Thank you for your understanding... And thank you very much for @vinx13 for fixing!