mm: hugetlb_vmemmap: include missing linux/moduleparam.h

The kernel test robot reported build failures with a 'randconfig' on s390:
>> mm/hugetlb_vmemmap.c:421:11: error: a function declaration without a
prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
   core_param(hugetlb_free_vmemmap, vmemmap_optimize_enabled, bool, 0);
             ^

Link: https://lore.kernel.org/linux-mm/[email protected]/
Link: https://lkml.kernel.org/r/patch.git-296b83ca939b.your-ad-here.call-01667411912-ext-5073@work.hours
Fixes: 3015224 ("mm: hugetlb_vmemmap: replace early_param() with core_param()")
Signed-off-by: Vasily Gorbik <[email protected]>
Reported-by: kernel test robot <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

mm/hugetlb_vmemmap.c

@@ -11,6 +11,7 @@
 #define pr_fmt(fmt)	"HugeTLB: " fmt
 
 #include <linux/pgtable.h>
+#include <linux/moduleparam.h>
 #include <linux/bootmem_info.h>
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>