patch 8.1.2402: typos and other small things

Problem:    Typos and other small things.
Solution:   Small fixes.
diff --git a/src/message.c b/src/message.c
index 4a3389c..9ecd194 100644
--- a/src/message.c
+++ b/src/message.c
@@ -1455,7 +1455,7 @@
 
 /*
  * Output 'len' characters in 'str' (including NULs) with translation
- * if 'len' is -1, output upto a NUL character.
+ * if 'len' is -1, output up to a NUL character.
  * Use attributes 'attr'.
  * Return the number of characters it takes on the screen.
  */
@@ -1599,7 +1599,7 @@
 #endif
 
 /*
- * Output the string 'str' upto a NUL character.
+ * Output the string 'str' up to a NUL character.
  * Return the number of characters it takes on the screen.
  *
  * If K_SPECIAL is encountered, then it is taken in conjunction with the