xen/arm32: mm: Rename 'first' to 'root' in init_secondary_pagetables()

The arm32 version of init_secondary_pagetables() will soon be re-used
for arm64 as well where the root table starts at level 0 rather than level 1.

So rename 'first' to 'root'.

Signed-off-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Elias El Yandouzi <eliasely@amazon.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>

xen/arch/arm/mmu/smpboot.c

@@ -109,32 +109,30 @@ int prepare_secondary_mm(int cpu)
 #else
 int prepare_secondary_mm(int cpu)
 {
-    lpae_t *first;
+    lpae_t *root = alloc_xenheap_page();
 
-    first = alloc_xenheap_page(); /* root == first level on 32-bit 3-level trie */
-
-    if ( !first )
+    if ( !root )
     {
-        printk("CPU%u: Unable to allocate the first page-table\n", cpu);
+        printk("CPU%u: Unable to allocate the root page-table\n", cpu);
         return -ENOMEM;
     }
 
     /* Initialise root pagetable from root of boot tables */
-    memcpy(first, per_cpu(xen_pgtable, 0), PAGE_SIZE);
-    per_cpu(xen_pgtable, cpu) = first;
+    memcpy(root, per_cpu(xen_pgtable, 0), PAGE_SIZE);
+    per_cpu(xen_pgtable, cpu) = root;
 
     if ( !init_domheap_mappings(cpu) )
     {
         printk("CPU%u: Unable to prepare the domheap page-tables\n", cpu);
         per_cpu(xen_pgtable, cpu) = NULL;
-        free_xenheap_page(first);
+        free_xenheap_page(root);
         return -ENOMEM;
     }
 
     clear_boot_pagetables();
 
     /* Set init_ttbr for this CPU coming up */
-    set_init_ttbr(first);
+    set_init_ttbr(root);
 
     return 0;
 }