Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 459f2cb..db8005d 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -2858,7 +2858,7 @@
 	/*
 	 * struct PFX_eckd_data has up to 2 byte as extended parameter
 	 * this is needed for write full track and has to be mentioned
-	 * seperately
+	 * separately
 	 * add 8 instead of 2 to keep 8 byte boundary
 	 */
 	pfx_datasize = sizeof(struct PFX_eckd_data) + 8;