core/pldm: Fix dangling point issue

When calling pldm_platform_init() and the GET_PDR PLDM
request fails, the 'pdrs_repo' global variable is freed
but becomes a dangling pointer. Subsequent calls to
pldm_platform_init will lead to an invalid read.

==28652== Invalid read of size 8
==28652==    at 0x40A4C8: pldm_pdr_destroy (pdr.c:130)
==28652==    by 0x424BA3: pdr_init_complete (pldm-platform-requests.c:42)
==28652==    by 0x4274DA: pldm_platform_load_pdrs (pldm-platform-requests.c:1170)
==28652==    by 0x42759C: pdrs_init (pldm-platform-requests.c:1190)
==28652==    by 0x427703: pldm_platform_init (pldm-platform-requests.c:1221)

Signed-off-by: Abhishek Singh Tomar <[email protected]>
Signed-off-by: Reza Arbab <[email protected]>

core/pldm/pldm-platform-requests.c

@@ -38,8 +38,10 @@ static void pdr_init_complete(bool success)
 	if (!success) {
 		pdr_ready = false;
 
-		if (pdrs_repo)
+		if (pdrs_repo) {
 			pldm_pdr_destroy(pdrs_repo);
+			pdrs_repo = NULL;
+		}
 		return;
 	}