khugepaged: selftests: fix timeout condition in wait_for_scan()

The loop exits with "timeout" set to -1 and not to 0 so the test needs to
be fixed.

Fixes: e7b592f ("khugepaged: add self test")
Signed-off-by: Dan Carpenter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Zi Yan <[email protected]>
Cc: William Kucharski <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: John Hubbard <[email protected]>
Link: http://lkml.kernel.org/r/20200605110736.GH978434@mwanda
Acked-by: Kirill A. Shutemov <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Dan Carpenter

tools/testing/selftests/vm/khugepaged.c

@@ -502,7 +502,7 @@ static bool wait_for_scan(const char *msg, char *p)
 
 	madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE);
 
-	return !timeout;
+	return timeout == -1;
 }
 
 static void alloc_at_fault(void)