mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info

We should check the VM_UNITIALIZED flag in s_show().  If this flag is
set, that said, the vm_struct is not fully initialized.  So it is
unnecessary to try to show the information contained in vm_struct.

We checked this flag in show_numa_info(), but I think it's better to
check it earlier.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>