Bugfix: fix typo in Pyarmnn README example code
Bugfix: fix typo in Pyarmnn README example code

Signed-off-by: Francis Murtagh <e59f6df1240b2b6c2b05aa682b1b9d01b9505720@arm.com>
Change-Id: Ib2c219c976dd37e570681442e15e414cdb61b3f6

ARM-software/armnn,ARM-software/armnn,ARM-software/armnn