firewire: core: remove an always false test

struct fw_cdev_allocate_iso_resource.bandwidth is unsigned.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 27ac423..13573e8 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -1366,8 +1366,7 @@
 	int ret;
 
 	if ((request->channels == 0 && request->bandwidth == 0) ||
-	    request->bandwidth > BANDWIDTH_AVAILABLE_INITIAL ||
-	    request->bandwidth < 0)
+	    request->bandwidth > BANDWIDTH_AVAILABLE_INITIAL)
 		return -EINVAL;
 
 	r  = kmalloc(sizeof(*r), GFP_KERNEL);