selinux: fix build warning by removing the unused sid variable

This patch remove the unused variable sid
This fix the following build warning:
security/selinux/hooks.c:2921:6: warning: variable 'sid' set but not used [-Wunused-but-set-variable]
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/hooks.c

@@ -2918,13 +2918,12 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
 {
 	const struct task_security_struct *tsec = current_security();
 	struct superblock_security_struct *sbsec;
-	u32 sid, newsid, clen;
+	u32 newsid, clen;
 	int rc;
 	char *context;
 
 	sbsec = dir->i_sb->s_security;
 
-	sid = tsec->sid;
 	newsid = tsec->create_sid;
 
 	rc = selinux_determine_inode_label(current_security(),