mm/hugetlb.c: fix duplicate variable

It's confusing that set_max_huge_pages() contained two different
variables named "ret", and although the code works correctly this should
be fixed.

The inner of the two variables can simply be removed.

Spotted by sparse.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc:  "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hugetlb.c

@@ -603,7 +603,6 @@ static unsigned long set_max_huge_pages(unsigned long count)
 	}
 
 	while (count > persistent_huge_pages) {
-		int ret;
 		/*
 		 * If this allocation races such that we no longer need the
 		 * page, free_huge_page will handle it by freeing the page