patch 8.1.2243: typos in comments

Problem:    Typos in comments.
Solution:   Fix the typos. (Dominique Pelle, closes #5160)  Also adjust
            formatting a bit.
diff --git a/src/option.c b/src/option.c
index 1140a01..935ee2d 100644
--- a/src/option.c
+++ b/src/option.c
@@ -4877,7 +4877,7 @@
 	    home_replace(NULL, *valuep, buf, size, FALSE);
 
 	    // If the option value is longer than MAXPATHL, we need to append
-	    // earch comma separated part of the option separately, so that it
+	    // each comma separated part of the option separately, so that it
 	    // can be expanded when read back.
 	    if (size >= MAXPATHL && (flags & P_COMMA) != 0
 					   && vim_strchr(*valuep, ',') != NULL)