transport: free local and remote refs in transport_push()

Fix memory leaks in transport_push(), where remote_refs and local_refs
are never freed.

116 bytes in 1 blocks are definitely lost in loss record 56 of 103
   at 0x484486F: malloc (vg_replace_malloc.c:381)
   by 0x4938D7E: strdup (strdup.c:42)
   by 0x628418: xstrdup (wrapper.c:39)
   by 0x4FD454: process_capabilities (connect.c:232)
   by 0x4FD454: get_remote_heads (connect.c:354)
   by 0x610A38: handshake (transport.c:333)
   by 0x612B02: transport_push (transport.c:1302)
   by 0x4803D6: push_with_options (push.c:357)
   by 0x4811D6: do_push (push.c:414)
   by 0x4811D6: cmd_push (push.c:650)
   by 0x405210: run_builtin (git.c:465)
   by 0x405210: handle_builtin (git.c:719)
   by 0x406363: run_argv (git.c:786)
   by 0x406363: cmd_main (git.c:917)
   by 0x404F17: main (common-main.c:56)

5,912 (388 direct, 5,524 indirect) bytes in 2 blocks are definitely lost in loss record 98 of 103
   at 0x4849464: calloc (vg_replace_malloc.c:1328)
   by 0x628705: xcalloc (wrapper.c:150)
   by 0x5C216D: alloc_ref_with_prefix (remote.c:975)
   by 0x5C232A: alloc_ref (remote.c:983)
   by 0x5C232A: one_local_ref (remote.c:2299)
   by 0x5C232A: one_local_ref (remote.c:2289)
   by 0x5BDB03: do_for_each_repo_ref_iterator (iterator.c:418)
   by 0x5B4C4F: do_for_each_ref (refs.c:1486)
   by 0x5B4C4F: refs_for_each_ref (refs.c:1492)
   by 0x5B4C4F: for_each_ref (refs.c:1497)
   by 0x5C6ADF: get_local_heads (remote.c:2310)
   by 0x612A85: transport_push (transport.c:1286)
   by 0x4803D6: push_with_options (push.c:357)
   by 0x4811D6: do_push (push.c:414)
   by 0x4811D6: cmd_push (push.c:650)
   by 0x405210: run_builtin (git.c:465)
   by 0x405210: handle_builtin (git.c:719)
   by 0x406363: run_argv (git.c:786)
   by 0x406363: cmd_main (git.c:917)

Signed-off-by: Frantisek Hrbata <frantisek@hrbata.com>
Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

transport.c

@@ -1419,6 +1419,8 @@ int transport_push(struct repository *r,
 		fprintf(stderr, "Everything up-to-date\n");
 
 done:
+	free_refs(local_refs);
+	free_refs(remote_refs);
 	return ret;
 }