Fix error in AABB calculation for particles with USERDATA

Selecting "Generate AABB" on a 3D particle node in the editor would not work
and printed an error about incorrect buffer size if the particle shader used
one or more of the USERDATA build-ins.

drivers/gles3/storage/particles_storage.cpp

@@ -395,7 +395,7 @@ AABB ParticlesStorage::particles_get_current_aabb(RID p_particles) {
 		bool first = true;
 
 		const uint8_t *data_ptr = (const uint8_t *)buffer.ptr();
-		uint32_t particle_data_size = sizeof(ParticleInstanceData3D) + sizeof(float) * particles->userdata_count;
+		uint32_t particle_data_size = sizeof(ParticleInstanceData3D);
 
 		for (int i = 0; i < total_amount; i++) {
 			const ParticleInstanceData3D &particle_data = *(const ParticleInstanceData3D *)&data_ptr[particle_data_size * i];

servers/rendering/renderer_rd/storage_rd/particles_storage.cpp

@@ -620,8 +620,9 @@ AABB ParticlesStorage::particles_get_current_aabb(RID p_particles) {
 		total_amount *= particles->trail_bind_poses.size();
 	}
 
+	uint32_t particle_data_size = sizeof(ParticleData) + sizeof(float) * 4 * particles->userdata_count;
 	Vector<uint8_t> buffer = RD::get_singleton()->buffer_get_data(particles->particle_buffer);
-	ERR_FAIL_COND_V(buffer.size() != (int)(total_amount * sizeof(ParticleData)), AABB());
+	ERR_FAIL_COND_V(buffer.size() != (int)(total_amount * particle_data_size), AABB());
 
 	Transform3D inv = particles->emission_transform.affine_inverse();
 
@@ -630,7 +631,6 @@ AABB ParticlesStorage::particles_get_current_aabb(RID p_particles) {
 		bool first = true;
 
 		const uint8_t *data_ptr = (const uint8_t *)buffer.ptr();
-		uint32_t particle_data_size = sizeof(ParticleData) + sizeof(float) * particles->userdata_count;
 
 		for (int i = 0; i < total_amount; i++) {
 			const ParticleData &particle_data = *(const ParticleData *)&data_ptr[particle_data_size * i];