fix(static-checks): fix cppcheck warnings

Fix some cppcheck warnings.

Signed-off-by: Shruti Gupta <shruti.gupta@arm.com>
Change-Id: I3f47ef5a54924d48c5e78cc3a38cc3d7508b24aa
diff --git a/lib/attestation/src/attestation_utils.c b/lib/attestation/src/attestation_utils.c
index 31a5189..c985f74 100644
--- a/lib/attestation/src/attestation_utils.c
+++ b/lib/attestation/src/attestation_utils.c
@@ -120,10 +120,8 @@
 	return 0;
 }
 
-int attestation_heap_ctx_unassign_pe(struct buffer_alloc_ctx *ctx)
+int attestation_heap_ctx_unassign_pe(void)
 {
-	assert(ctx != NULL);
-
 	if (attest_initialized == false) {
 		return -EINVAL;
 	}