powerpc/pseries/vas: Fix comment typo

The double `the' in line 807 is duplicated, remove one.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220718075553.70897-1-wangborong@cdjrlc.com