mailmap.c: fix a memory leak in free_mailap_{info,entry}()

In the free_mailmap_entry() code added in 0925ce4d49 (Add map_user()
and clear_mailmap() to mailmap, 2009-02-08) the intent was clearly to
clear the "me" structure, but while we freed parts of the
mailmap_entry structure, we didn't free the structure itself. The same
goes for the "mailmap_info" structure.

This brings the number of SANITIZE=leak failures in t4203-mailmap.sh
down from 50 to 49. Not really progress as far as the number of
failures is concerned, but as far as I can tell this fixes all leaks
in mailmap.c itself. There's still users of it such as builtin/log.c
that call read_mailmap() without a clear_mailmap(), but that's on
them.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/mailmap.c b/mailmap.c
index d1f7c0d..e1c8736 100644
--- a/mailmap.c
+++ b/mailmap.c
@@ -36,6 +36,7 @@ static void free_mailmap_info(void *p, const char *s)
 		 s, debug_str(mi->name), debug_str(mi->email));
 	free(mi->name);
 	free(mi->email);
+	free(mi);
 }
 
 static void free_mailmap_entry(void *p, const char *s)
@@ -51,6 +52,7 @@ static void free_mailmap_entry(void *p, const char *s)
 
 	me->namemap.strdup_strings = 1;
 	string_list_clear_func(&me->namemap, free_mailmap_info);
+	free(me);
 }
 
 /*