NTB: correct ntb_spad_count comment typo

The comment for ntb_spad_count incorrectly referred to ntb_mw_count.
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

include/linux/ntb.h

@@ -896,7 +896,7 @@ static inline int ntb_spad_is_unsafe(struct ntb_dev *ntb)
 }
 
 /**
- * ntb_mw_count() - get the number of scratchpads
+ * ntb_spad_count() - get the number of scratchpads
  * @ntb:	NTB device context.
  *
  * Hardware and topology may support a different number of scratchpads.