Buffer::Unmap no longer return boolean

Made no sense: What do you want to do when your buffer doesn't unmap ?
Tt now throw a warning by itself in case of failure


Former-commit-id: f776af16787316bbe1d55686a1db2c2e0f79d210

src/Nazara/Utility/StaticMesh.cpp

@@ -79,8 +79,7 @@ bool NzStaticMesh::GenerateAABB()
 		vertex++;
 	}
 
-	if (!m_vertexBuffer->Unmap())
-		NazaraWarning("Failed to unmap vertex buffer");
+	m_vertexBuffer->Unmap();
 
 	return true;
 }