target: Allow for built-in target modules

In target_fabric_configfs_init(), we should allow fabric_mod to be NULL,
since THIS_MODULE is NULL for built-in modules.  The main method of
using the target code may be as modules, but having everything built-in
is useful eg to be able to do quick testing with "qemu -kernel".

In any case, we shouldn't bomb out fabric registration for a perfectly
valid configuration, so simply drop the check of fabric_mod.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_configfs.c

@@ -306,10 +306,6 @@ struct target_fabric_configfs *target_fabric_configfs_init(
 {
 	struct target_fabric_configfs *tf;
 
-	if (!(fabric_mod)) {
-		printk(KERN_ERR "Missing struct module *fabric_mod pointer\n");
-		return ERR_PTR(-EINVAL);
-	}
 	if (!(name)) {
 		printk(KERN_ERR "Unable to locate passed fabric name\n");
 		return ERR_PTR(-EINVAL);