mm: vmscan: use sysfs_emit() to instead of scnprintf()

Replace open-coded snprintf() with sysfs_emit() to simplify the code.

Link: https://lkml.kernel.org/r/202211241929015476424@zte.com.cnSigned-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/vmscan.c

@@ -5407,7 +5407,7 @@ static ssize_t show_enabled(struct kobject *kobj, struct kobj_attribute *attr, c
 	if (arch_has_hw_nonleaf_pmd_young() && get_cap(LRU_GEN_NONLEAF_YOUNG))
 		caps |= BIT(LRU_GEN_NONLEAF_YOUNG);
 
-	return snprintf(buf, PAGE_SIZE, "0x%04x\n", caps);
+	return sysfs_emit(buf, "0x%04x\n", caps);
 }
 
 /* see Documentation/admin-guide/mm/multigen_lru.rst for details */