KVM: PPC: Fix typo on H_DISABLE_AND_GET hcall

On PAPR+ the hcall() on 0x1B0 is called H_DISABLE_AND_GET, but got
defined as H_DISABLE_AND_GETC instead.

This define was introduced with a typo in commit <b13a96cf>
("[PATCH] powerpc: Extends HCALL interface for InfiniBand usage"), and was
later used without having the typo noticed.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200707004812.190765-1-leobras.c@gmail.com