befs: avoid dereferencing dentry twice

No need to dereference dentry twice to get the name when we already have
it stored in a local variable.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>

fs/befs/linuxvfs.c

@@ -179,7 +179,7 @@ befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 		kfree(utfname);
 
 	} else {
-		ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
+		ret = befs_btree_find(sb, ds, name, &offset);
 	}
 
 	if (ret == BEFS_BT_NOT_FOUND) {