doc: Update the name of profiling based on sysfs

The ./kernel/ksysfs.c defines 'profiling' w/o 'profile' like
"KERNEL_ATTR_RW(profiling)".  We need to synchronize the content between ksys.c
source and kernel doc.
Signed-off-by: NHyeonjun Lim <hjoon0510@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Documentation/ABI/testing/sysfs-profiling

-What:		/sys/kernel/profile
+What:		/sys/kernel/profiling
 Date:		September 2008
 Contact:	Dave Hansen <dave@linux.vnet.ibm.com>
 Description:
-		/sys/kernel/profile is the runtime equivalent
+		/sys/kernel/profiling is the runtime equivalent
 		of the boot-time profile= option.
 
 		You can get the same effect running:
 
-			echo 2 > /sys/kernel/profile
+			echo 2 > /sys/kernel/profiling
 
 		as you would by issuing profile=2 on the boot
 		command line.