Fixed spelling / typos (from PowerDNS:codespell)
diff --git a/programs/aes/aescrypt2.c b/programs/aes/aescrypt2.c
index 1cedcc7..4c1f8ea 100644
--- a/programs/aes/aescrypt2.c
+++ b/programs/aes/aescrypt2.c
@@ -320,7 +320,7 @@
         }
 
         /*
-         * Substract the IV + HMAC length.
+         * Subtract the IV + HMAC length.
          */
         filesize -= ( 16 + 32 );