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/spellsuggest.c b/src/spellsuggest.c
index 255f94d..f21d55f 100644
--- a/src/spellsuggest.c
+++ b/src/spellsuggest.c
@@ -112,7 +112,7 @@
 #define SCORE_THRES3	100	// word count threshold for COMMON3
 
 // When trying changed soundfold words it becomes slow when trying more than
-// two changes.  With less then two changes it's slightly faster but we miss a
+// two changes.  With less than two changes it's slightly faster but we miss a
 // few good suggestions.  In rare cases we need to try three of four changes.
 #define SCORE_SFMAX1	200	// maximum score for first try
 #define SCORE_SFMAX2	300	// maximum score for second try