kernel: vm: Fix incorrect argument passing in 'vm map' test

vm map takes arg 3 as virtual address. And same needs
to be passed to retrieve aspace. Fix this by passing
right arg.

Test: Ran 'vm map' test
        ] vm map 0xc0000000 0xffff000ff0000000 1 0x0
        arch_mmu_map returns 0

Signed-off-by: Chintan Pandya <chintanpandya@google.com>

kernel/vm/vm.c

@@ -166,9 +166,9 @@ usage:
     } else if (!strcmp(argv[1].str, "map")) {
         if (argc < 6) goto notenoughargs;
 
-        vmm_aspace_t *aspace = vaddr_to_aspace((void *)argv[2].u);
+        vmm_aspace_t *aspace = vaddr_to_aspace((void *)argv[3].u);
         if (!aspace) {
-            printf("ERROR: outside of any address space\n");
+            printf("ERROR: %p outside of any address space\n", (void *)argv[3].u);
             return -1;
         }