msgbuf: Rename 'destroy' APIs to 'complete'

Change the language to better reflect the intent, with the impending
introduction of the ability to 'discard' a msgbuf instance.

Change-Id: Idbb79dcc2587a8baef67ffd405e0bc77e66fe995
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/tests/dsp/pdr.cpp b/tests/dsp/pdr.cpp
index 3b72cb7..b85ba2a 100644
--- a/tests/dsp/pdr.cpp
+++ b/tests/dsp/pdr.cpp
@@ -81,7 +81,7 @@
     pldm_msgbuf_extract_uint8(buf, association_pdr_test.num_children);
     getEntity(buf, child_entity);
 
-    ASSERT_EQ(pldm_msgbuf_destroy_consumed(buf), 0);
+    ASSERT_EQ(pldm_msgbuf_complete_consumed(buf), 0);
 
     EXPECT_TRUE(association_pdr_test == association_pdr);
     EXPECT_TRUE(container_entity == container_entity1);