evm: remove set but not used variable 'xattr'

Fixes gcc '-Wunused-but-set-variable' warning:

security/integrity/evm/evm_main.c: In function 'init_evm':
security/integrity/evm/evm_main.c:566:21: warning:
 variable 'xattr' set but not used [-Wunused-but-set-variable]

Commit 21af7663 ("EVM: turn evm_config_xattrnames into a list")
defined and set "xattr", but never used it.

[zohar@linux.ibm.com: tweaked the patch description explanation]
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

security/integrity/evm/evm_main.c

@@ -563,7 +563,6 @@ static int __init init_evm(void)
 {
 	int error;
 	struct list_head *pos, *q;
-	struct xattr_list *xattr;
 
 	evm_init_config();
 
@@ -580,11 +579,8 @@ static int __init init_evm(void)
 error:
 	if (error != 0) {
 		if (!list_empty(&evm_config_xattrnames)) {
-			list_for_each_safe(pos, q, &evm_config_xattrnames) {
-				xattr = list_entry(pos, struct xattr_list,
-						   list);
+			list_for_each_safe(pos, q, &evm_config_xattrnames)
 				list_del(pos);
-			}
 		}
 	}