patch 9.0.2073: typo in quickfix.c comments

Problem:  typo in quickfix.c comments
Solution: fix them

closes: #13422

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
diff --git a/src/quickfix.c b/src/quickfix.c
index 45b58c4..207331f 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -987,8 +987,8 @@
 }
 
 /*
- * Parse the match for error number ('%n') pattern in regmatch.
- * Return the matched value in "fields->enr".
+ * Parse the match for buffer number ('%b') pattern in regmatch.
+ * Return the matched value in "fields->bnr".
  */
     static int
 qf_parse_fmt_b(regmatch_T *rmp, int midx, qffields_T *fields)