[FRR] Adding patch to fix isisd memory leak

Fixing issue
Repeat command "ip router isis 5" and "no ip router isis 5", there is memory leak in isisd

- How I did it
Root cause of the problem:

The isis_lfa_excluded_ifaces_clear function in isis_lfa.c only clears the elements when clearing the hash table, but does not release the table itself.

Release memory in hash_free:

MTYPE_HASH*2
MTYPE_HASH_INDEX * 1
MTYPE_LINK_NODE * 1

Modification method:

Add hash_free after hash_clean, and there is no need to empty it after release.

- How to verify it
Repeat command "ip router isis 5" and "no ip router isis 5", no memory leak in isisd

src/sonic-frr/patch/0030-isisd-Fix-memory-leak.patch

@@ -0,0 +1,25 @@
+From 45f5ba53f94d97c4b1cf31fd0bca01167cd727cb Mon Sep 17 00:00:00 2001
+From: Tyler Li <litiezheng@ieisystem.com>
+Date: Tue, 9 Apr 2024 14:43:19 +0800
+Subject: [PATCH] isisd: Fix memory leak
+
+Signed-off-by: Tyler Li <litiezheng@ieisystem.com>
+---
+ isisd/isis_lfa.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/isisd/isis_lfa.c b/isisd/isis_lfa.c
+index 84aac24d5..e99c4b805 100644
+--- a/isisd/isis_lfa.c
++++ b/isisd/isis_lfa.c
+@@ -255,6 +255,7 @@ void isis_lfa_excluded_ifaces_clear(struct isis_circuit *circuit, int level)
+ {
+ 	hash_clean(circuit->lfa_excluded_ifaces[level - 1],
+ 		   lfa_excl_interface_hash_free);
++	hash_free(circuit->lfa_excluded_ifaces[level - 1]);
+ }
+
+ /**
+-- 
+2.37.1
+

src/sonic-frr/patch/series

@@ -27,3 +27,4 @@
 0027-lib-Do-not-convert-EVPN-prefixes-into-IPv4-IPv6-if-n.patch
 0028-zebra-fix-parse-attr-problems-for-encap.patch
 0029-zebra-nhg-fix-on-intf-up.patch
+0030-isisd-Fix-memory-leak.patch