xen/arm: Add 0x prefix when printing memory size in construct_domU

Printing memory size in hex without 0x prefix can be misleading, so
add it. Also, take the opportunity to adhere to 80 chars line length
limit by moving the printk arguments to the next line.

Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com>
Acked-by: Julien Grall <jgrall@amazon.com>

xen/arch/arm/domain_build.c

@@ -3774,7 +3774,8 @@ static int __init construct_domU(struct domain *d,
     if ( rc != 0 )
         return rc;
 
-    printk("*** LOADING DOMU cpus=%u memory=%"PRIx64"KB ***\n", d->max_vcpus, mem);
+    printk("*** LOADING DOMU cpus=%u memory=%#"PRIx64"KB ***\n",
+           d->max_vcpus, mem);
 
     kinfo.vpl011 = dt_property_read_bool(node, "vpl011");