comedi: convert sysfs snprintf to sysfs_emit

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: Xuezhi Zhang <zhangxuezhi1@coolpad.com>
Link: https://lore.kernel.org/r/20220901013423.418464-1-zhangxuezhi3@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Xuezhi Zhang

drivers/comedi/comedi_fops.c

@@ -396,7 +396,7 @@ static ssize_t max_read_buffer_kb_show(struct device *csdev,
 	mutex_unlock(&dev->mutex);
 
 	comedi_dev_put(dev);
-	return snprintf(buf, PAGE_SIZE, "%u\n", size);
+	return sysfs_emit(buf, "%u\n", size);
 }
 
 static ssize_t max_read_buffer_kb_store(struct device *csdev,
@@ -452,7 +452,7 @@ static ssize_t read_buffer_kb_show(struct device *csdev,
 	mutex_unlock(&dev->mutex);
 
 	comedi_dev_put(dev);
-	return snprintf(buf, PAGE_SIZE, "%u\n", size);
+	return sysfs_emit(buf, "%u\n", size);
 }
 
 static ssize_t read_buffer_kb_store(struct device *csdev,
@@ -509,7 +509,7 @@ static ssize_t max_write_buffer_kb_show(struct device *csdev,
 	mutex_unlock(&dev->mutex);
 
 	comedi_dev_put(dev);
-	return snprintf(buf, PAGE_SIZE, "%u\n", size);
+	return sysfs_emit(buf, "%u\n", size);
 }
 
 static ssize_t max_write_buffer_kb_store(struct device *csdev,
@@ -565,7 +565,7 @@ static ssize_t write_buffer_kb_show(struct device *csdev,
 	mutex_unlock(&dev->mutex);
 
 	comedi_dev_put(dev);
-	return snprintf(buf, PAGE_SIZE, "%u\n", size);
+	return sysfs_emit(buf, "%u\n", size);
 }
 
 static ssize_t write_buffer_kb_store(struct device *csdev,