powernv/pci: Allow any write trigger the diag dump

Make the dump trigger off any input rather than just '1'. This allows you
to write "echo 1> dump_diag_data" and it'll do what you want rather than
erroring out pointlessly.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190912052945.12589-2-oohall@gmail.com

arch/powerpc/platforms/powernv/pci-ioda.c

@@ -3093,9 +3093,6 @@ static int pnv_pci_diag_data_set(void *data, u64 val)
 	struct pnv_phb *phb = data;
 	s64 ret;
 
-	if (val != 1ULL)
-		return -EINVAL;
-
 	/* Retrieve the diag data from firmware */
 	ret = opal_pci_get_phb_diag_data2(phb->opal_id, phb->diag_data,
 					  phb->diag_data_size);