Replace remaining references to "driverfs" with "sysfs".

Globally, s/driverfs/sysfs/g.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 7fd095e..fe7ef33 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -103,7 +103,7 @@
 #endif
 
 /*
- * register_cpu - Setup a driverfs device for a CPU.
+ * register_cpu - Setup a sysfs device for a CPU.
  * @cpu - cpu->hotpluggable field set to 1 will generate a control file in
  *	  sysfs for this CPU.
  * @num - CPU number to use when creating the device.