xen/setup: Only print "Freeing XXX-YYY pfn range: Z pages freed" if Z > 0

Otherwise we can get these meaningless:
Freeing  bad80-badf4 pfn range: 0 pages freed

We also can do this for the summary ones - no point of printing
"Set 0 page(s) to 1-1 mapping"
Acked-by: David Vrabel <david.vrabel@citrix.com>
[v1: Extended to the summary printks]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

arch/x86/xen/setup.c

@@ -114,6 +114,7 @@ static unsigned long __init xen_release_chunk(unsigned long start,
 			len++;
 		}
 	}
+	if (len)
 		printk(KERN_INFO "Freeing  %lx-%lx pfn range: %lu pages freed\n",
 		       start, end, len);
 
@@ -162,7 +163,9 @@ static unsigned long __init xen_set_identity_and_release(
 		}
 	}
 
+	if (released)
 		printk(KERN_INFO "Released %lu pages of unused memory\n", released);
+	if (identity)
 		printk(KERN_INFO "Set %ld page(s) to 1-1 mapping\n", identity);
 
 	return released;