x86/xen: simplify xen_oldmem_pfn_is_ram()

Let's simplify return handling.

Link: https://lkml.kernel.org/r/20211005121430.30136-3-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/xen/mmu_hvm.c

@@ -21,23 +21,10 @@ static int xen_oldmem_pfn_is_ram(unsigned long pfn)
 		.domid = DOMID_SELF,
 		.pfn = pfn,
 	};
-	int ram;
 
 	if (HYPERVISOR_hvm_op(HVMOP_get_mem_type, &a))
 		return -ENXIO;
-
-	switch (a.mem_type) {
-	case HVMMEM_mmio_dm:
-		ram = 0;
-		break;
-	case HVMMEM_ram_rw:
-	case HVMMEM_ram_ro:
-	default:
-		ram = 1;
-		break;
-	}
-
-	return ram;
+	return a.mem_type != HVMMEM_mmio_dm;
 }
 #endif