tree-wide: fix misspelling of "definition" in comments

"Definition" is misspelled "defintion" in several comments; this
patch fixes them. No code changes.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/scsi/aic94xx/aic94xx_reg_def.h b/drivers/scsi/aic94xx/aic94xx_reg_def.h
index a43e8cd..28aaf34 100644
--- a/drivers/scsi/aic94xx/aic94xx_reg_def.h
+++ b/drivers/scsi/aic94xx/aic94xx_reg_def.h
@@ -1,5 +1,5 @@
 /*
- * Aic94xx SAS/SATA driver hardware registers defintions.
+ * Aic94xx SAS/SATA driver hardware registers definitions.
  *
  * Copyright (C) 2004 Adaptec, Inc.  All rights reserved.
  * Copyright (C) 2004 David Chaw <david_chaw@adaptec.com>