page_pool: fix incorrect mp_ops error handling

Minor fix to the memory provider error handling, we should be jumping to
free_ptr_ring in this error case rather than returning directly.

Found by code-inspection.

Cc: [e-mail]

Fixes: b400f4b87430 ("page_pool: Set `dma_sync` to false for devmem memory provider")
Signed-off-by: Mina Almasry <[e-mail]>
Reviewed-by: Samiullah Khawaja <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

net/core/page_pool.c

···
 	}
 
 	if (pool->mp_ops) {
-		if (!pool->dma_map || !pool->dma_sync)
-			return -EOPNOTSUPP;
+		if (!pool->dma_map || !pool->dma_sync) {
+			err = -EOPNOTSUPP;
+			goto free_ptr_ring;
+		}
 
 		if (WARN_ON(!is_kernel_rodata((unsigned long)pool->mp_ops))) {
 			err = -EFAULT;