Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/sound/oss/audio.c b/sound/oss/audio.c
index 7df48a2..4b958b1 100644
--- a/sound/oss/audio.c
+++ b/sound/oss/audio.c
@@ -514,7 +514,7 @@
 				count += dmap->bytes_in_use;	/* Pointer wrap not handled yet */
 			count += dmap->byte_counter;
 		
-			/* Substract current count from the number of bytes written by app */
+			/* Subtract current count from the number of bytes written by app */
 			count = dmap->user_counter - count;
 			if (count < 0)
 				count = 0;
@@ -931,7 +931,7 @@
 			if (count < dmap_out->fragment_size && dmap_out->qhead != 0)
 				count += dmap_out->bytes_in_use;	/* Pointer wrap not handled yet */
 			count += dmap_out->byte_counter;
-			/* Substract current count from the number of bytes written by app */
+			/* Subtract current count from the number of bytes written by app */
 			count = dmap_out->user_counter - count;
 			if (count < 0)
 				count = 0;