khugepaged: avoid usage of uninitialized variable 'isolated'

In file included from include/trace/events/huge_memory.h:7:0,
                 from mm/huge_memory.c:62:
include/linux/tracepoint.h:141:5: warning: `isolated' may be used uninitialized in this function [-Wmaybe-uninitialized]
     ((void(*)(proto))(it_func))(args); \
     ^
mm/huge_memory.c:2327:6: note: `isolated' was declared here
  int isolated, result = 0;

We make use of isolated in error path before it get initialized.

Signed-off-by: Kirill A. Shutemov <[email protected]>
Cc: Ebru Akagunduz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: kiryl

mm/huge_memory.c

@@ -2594,7 +2594,7 @@ static void collapse_huge_page(struct mm_struct *mm,
 	pgtable_t pgtable;
 	struct page *new_page;
 	spinlock_t *pmd_ptl, *pte_ptl;
-	int isolated, result = 0;
+	int isolated = 0, result = 0;
 	unsigned long hstart, hend;
 	struct mem_cgroup *memcg;
 	unsigned long mmun_start;	/* For mmu_notifiers */