patch 8.2.3914: various spelling mistakes in comments

Problem:    Various spelling mistakes in comments.
Solution:   Fix the mistakes. (Dominique Pellé, closes #9416)
diff --git a/src/cindent.c b/src/cindent.c
index 42b46e4..9f1db03 100644
--- a/src/cindent.c
+++ b/src/cindent.c
@@ -1223,7 +1223,7 @@
 	if (*s == ')' && cin_nocode(s + 1))
 	{
 	    // ')' at the end: may have found a match
-	    // Check for he previous line not to end in a backslash:
+	    // Check for the previous line not to end in a backslash:
 	    //       #if defined(x) && {backslash}
 	    //		 defined(y)
 	    lnum = first_lnum - 1;
@@ -1792,7 +1792,7 @@
     buf->b_ind_unclosed2 = sw;
 
     // Suppress ignoring spaces from the indent of a line starting with an
-    // unclosed parentheses.
+    // unclosed parenthesis.
     buf->b_ind_unclosed_noignore = 0;
 
     // If the opening paren is the last nonwhite character on the line, and
@@ -1804,11 +1804,11 @@
     // an unclosed parenthesis.
     buf->b_ind_unclosed_whiteok = 0;
 
-    // Indent a closing parentheses under the line start of the matching
-    // opening parentheses.
+    // Indent a closing parenthesis under the line start of the matching
+    // opening parenthesis.
     buf->b_ind_matching_paren = 0;
 
-    // Indent a closing parentheses under the previous line.
+    // Indent a closing parenthesis under the previous line.
     buf->b_ind_paren_prev = 0;
 
     // Extra indent for comments.