maillbox: bcm-flexrm-mailbox: handle cmpl_pool dma allocation failure

Handle 'cmpl_pool' dma memory allocation failure.

Fixes: a9a9da47f8e6 ("mailbox: no need to check return value of debugfs_create functions")
Signed-off-by: Rayagonda Kokatanur <[e-mail]>
Reviewed-by: Tyler Hicks <[e-mail]>
Signed-off-by: Jassi Brar <[e-mail]>

drivers/mailbox/bcm-flexrm-mailbox.c

···
 					  1 << RING_CMPL_ALIGN_ORDER, 0);
 	if (!mbox->cmpl_pool) {
 		ret = -ENOMEM;
+		goto fail_destroy_bd_pool;
 	}
 
 	/* Allocate platform MSIs for each ring */
···
 	platform_msi_domain_free_irqs(dev);
 fail_destroy_cmpl_pool:
 	dma_pool_destroy(mbox->cmpl_pool);
+fail_destroy_bd_pool:
 	dma_pool_destroy(mbox->bd_pool);
 fail:
 	return ret;