Style and language fixes from review

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
diff --git a/tests/include/test/drivers/cipher.h b/tests/include/test/drivers/cipher.h
index 96ab295..ef787f7 100644
--- a/tests/include/test/drivers/cipher.h
+++ b/tests/include/test/drivers/cipher.h
@@ -52,7 +52,7 @@
     /* If not PSA_SUCCESS, return this error code instead of processing the
      * function call. */
     psa_status_t forced_status;
-    /* Count the amount of times one of the keygen driver functions is called. */
+    /* Count the amount of times one of the cipher driver functions is called. */
     unsigned long hits;
 } test_driver_cipher_hooks_t;