patch 8.2.2160: various typos

Problem:    Various typos.
Solution:   Fix spelling mistakes. (closes #7494)
diff --git a/src/getchar.c b/src/getchar.c
index 3f2ad3c..cf2711b 100644
--- a/src/getchar.c
+++ b/src/getchar.c
@@ -2264,7 +2264,7 @@
 }
 
 /*
- * Check if typebuf.tb_buf[] contains a modifer plus key that can be changed
+ * Check if typebuf.tb_buf[] contains a modifier plus key that can be changed
  * into just a key, apply that.
  * Check from typebuf.tb_buf[typebuf.tb_off] to typebuf.tb_buf[typebuf.tb_off
  * + "max_offset"].