Revert duplicate "mm/hugetlb.c must #include <asm/io.h>"

This reverts commit 7cb93181629c613ee2b8f4ffe3446f8003074842, since we
did that patch twice, and the problem was already fixed earlier by
78a34ae29bf1c9df62a5bd0f0798b6c62a54d520.

Reported-by: Andi Kleen <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

mm/hugetlb.c

···
 #include <linux/mutex.h>
 #include <linux/bootmem.h>
 #include <linux/sysfs.h>
-#include <asm/io.h>
+
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include <asm/io.h>