rfkill: Use sysfs_emit() to instead of sprintf()

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the
value to be returned to user space.
Signed-off-by: Bo Liu <liubo03@inspur.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230206081641.3193-1-liubo03@inspur.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/rfkill/core.c

@@ -685,7 +685,7 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 {
 	struct rfkill *rfkill = to_rfkill(dev);
 
-	return sprintf(buf, "%s\n", rfkill->name);
+	return sysfs_emit(buf, "%s\n", rfkill->name);
 }
 static DEVICE_ATTR_RO(name);
 
@@ -694,7 +694,7 @@ static ssize_t type_show(struct device *dev, struct device_attribute *attr,
 {
 	struct rfkill *rfkill = to_rfkill(dev);
 
-	return sprintf(buf, "%s\n", rfkill_types[rfkill->type]);
+	return sysfs_emit(buf, "%s\n", rfkill_types[rfkill->type]);
 }
 static DEVICE_ATTR_RO(type);
 
@@ -703,7 +703,7 @@ static ssize_t index_show(struct device *dev, struct device_attribute *attr,
 {
 	struct rfkill *rfkill = to_rfkill(dev);
 
-	return sprintf(buf, "%d\n", rfkill->idx);
+	return sysfs_emit(buf, "%d\n", rfkill->idx);
 }
 static DEVICE_ATTR_RO(index);
 
@@ -712,7 +712,7 @@ static ssize_t persistent_show(struct device *dev,
 {
 	struct rfkill *rfkill = to_rfkill(dev);
 
-	return sprintf(buf, "%d\n", rfkill->persistent);
+	return sysfs_emit(buf, "%d\n", rfkill->persistent);
 }
 static DEVICE_ATTR_RO(persistent);
 
@@ -721,7 +721,7 @@ static ssize_t hard_show(struct device *dev, struct device_attribute *attr,
 {
 	struct rfkill *rfkill = to_rfkill(dev);
 
-	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_HW) ? 1 : 0 );
+	return sysfs_emit(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_HW) ? 1 : 0);
 }
 static DEVICE_ATTR_RO(hard);
 
@@ -730,7 +730,7 @@ static ssize_t soft_show(struct device *dev, struct device_attribute *attr,
 {
 	struct rfkill *rfkill = to_rfkill(dev);
 
-	return sprintf(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_SW) ? 1 : 0 );
+	return sysfs_emit(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_SW) ? 1 : 0);
 }
 
 static ssize_t soft_store(struct device *dev, struct device_attribute *attr,
@@ -764,7 +764,7 @@ static ssize_t hard_block_reasons_show(struct device *dev,
 {
 	struct rfkill *rfkill = to_rfkill(dev);
 
-	return sprintf(buf, "0x%lx\n", rfkill->hard_block_reasons);
+	return sysfs_emit(buf, "0x%lx\n", rfkill->hard_block_reasons);
 }
 static DEVICE_ATTR_RO(hard_block_reasons);
 
@@ -783,7 +783,7 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 {
 	struct rfkill *rfkill = to_rfkill(dev);
 
-	return sprintf(buf, "%d\n", user_state_from_blocked(rfkill->state));
+	return sysfs_emit(buf, "%d\n", user_state_from_blocked(rfkill->state));
 }
 
 static ssize_t state_store(struct device *dev, struct device_attribute *attr,