iscsi_ibft: use virt_to_phys instead of isa_virt_to_bus

As far as I can tell IBFT is a firmware table and has nothing to do with
the good old ISA bus.  And even if it the two would be the same on x86
anyway.  So remove the isa_virt_to_bus call in preparation of eventually
removing that API entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/firmware/iscsi_ibft_find.c

@@ -104,7 +104,7 @@ unsigned long __init find_ibft_region(unsigned long *sizep)
 
 	if (ibft_addr) {
 		*sizep = PAGE_ALIGN(ibft_addr->header.length);
-		return (u64)isa_virt_to_bus(ibft_addr);
+		return (u64)virt_to_phys(ibft_addr);
 	}
 
 	*sizep = 0;