oprofile: Fix oprofile_timer_exit() breakage

Removing remainings of oprofile_timer_exit() completly.
Signed-off-by: Robert Richter <robert.richter@amd.com>

arch/s390/oprofile/init.c

@@ -171,7 +171,6 @@ static int oprofile_hwsampler_init(struct oprofile_operations *ops)
 
 static void oprofile_hwsampler_exit(void)
 {
-	oprofile_timer_exit();
 	hwsampler_shutdown();
 }
 

drivers/oprofile/oprof.h

@@ -35,7 +35,6 @@ struct dentry;
 
 void oprofile_create_files(struct super_block *sb, struct dentry *root);
 int oprofile_timer_init(struct oprofile_operations *ops);
-void oprofile_timer_exit(void);
 #ifdef CONFIG_OPROFILE_NMI_TIMER
 int op_nmi_timer_init(struct oprofile_operations *ops);
 #else