clang-tidy: Fix bugprone-reserved-identifier

For example:

```
/usr/bin/clang-tidy -checks=-*, bugprone-reserved-identifier -export-fixes /tmp/tmpzm__u6tl/tmpcmikv8op.yaml -p=build /mnt/host/andrew/src/openbmc/libpldm/src/pdr.c
/mnt/host/andrew/src/openbmc/libpldm/build/../src/pdr.c:605:13: error: declaration uses identifier '_entity_association_pdr_add_entry', which is reserved in the global namespace [bugprone-reserved-identifier,-warnings-as-errors]
static void _entity_association_pdr_add_entry(pldm_entity_node *curr,
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            entity_association_pdr_add_entry
```

In the case of header guard macros, prefix them with `LIBPLDM_` and drop
the trailing `__`.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: I74809142cc428d2c014e0f7ba43e02d9a229eee2
diff --git a/src/pdr.c b/src/pdr.c
index b3a5d5a..b53f491 100644
--- a/src/pdr.c
+++ b/src/pdr.c
@@ -602,12 +602,12 @@
 	return false;
 }
 
-static void _entity_association_pdr_add_entry(pldm_entity_node *curr,
-					      pldm_pdr *repo, uint16_t size,
-					      uint8_t contained_count,
-					      uint8_t association_type,
-					      bool is_remote,
-					      uint16_t terminus_handle)
+static void entity_association_pdr_add_children(pldm_entity_node *curr,
+						pldm_pdr *repo, uint16_t size,
+						uint8_t contained_count,
+						uint8_t association_type,
+						bool is_remote,
+						uint16_t terminus_handle)
 {
 	uint8_t pdr[size];
 	uint8_t *start = pdr;
@@ -666,7 +666,7 @@
 		    sizeof(struct pldm_pdr_hdr) + sizeof(uint16_t) +
 		    sizeof(uint8_t) + sizeof(pldm_entity) + sizeof(uint8_t) +
 		    (num_logical_children * sizeof(pldm_entity));
-		_entity_association_pdr_add_entry(
+		entity_association_pdr_add_children(
 		    curr, repo, logical_pdr_size, num_logical_children,
 		    PLDM_ENTITY_ASSOCIAION_LOGICAL, is_remote, terminus_handle);
 	}
@@ -676,7 +676,7 @@
 		    sizeof(struct pldm_pdr_hdr) + sizeof(uint16_t) +
 		    sizeof(uint8_t) + sizeof(pldm_entity) + sizeof(uint8_t) +
 		    (num_physical_children * sizeof(pldm_entity));
-		_entity_association_pdr_add_entry(
+		entity_association_pdr_add_children(
 		    curr, repo, physical_pdr_size, num_physical_children,
 		    PLDM_ENTITY_ASSOCIAION_PHYSICAL, is_remote,
 		    terminus_handle);