patch 8.2.1547: various comment problems

Problem:    Various comment problems.
Solution:   Update comments.
diff --git a/src/mbyte.c b/src/mbyte.c
index 46d0392..0abb164 100644
--- a/src/mbyte.c
+++ b/src/mbyte.c
@@ -1607,7 +1607,7 @@
 {
     int		c;
 
-    // Need to convert to a wide character.
+    // Need to convert to a character number.
     if (*p >= 0x80)
     {
 	c = utf_ptr2char(p);
@@ -1762,7 +1762,7 @@
 }
 
 /*
- * Convert a UTF-8 byte sequence to a wide character.
+ * Convert a UTF-8 byte sequence to a character number.
  * If the sequence is illegal or truncated by a NUL the first byte is
  * returned.
  * For an overlong sequence this may return zero.