selinux: print leading 0x on ioctlcmd audits

ioctlcmd is currently printing hex numbers, but their is no leading
0x. Thus things like ioctlcmd=1234 are misleading, as the base is
not evident.

Correct this by adding 0x as a prefix, so ioctlcmd=1234 becomes
ioctlcmd=0x1234.
Signed-off-by: William Roberts <william.c.roberts@intel.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/lsm_audit.c

@@ -257,7 +257,7 @@ static void dump_common_audit_data(struct audit_buffer *ab,
 			audit_log_format(ab, " ino=%lu", inode->i_ino);
 		}
 
-		audit_log_format(ab, " ioctlcmd=%hx", a->u.op->cmd);
+		audit_log_format(ab, " ioctlcmd=0x%hx", a->u.op->cmd);
 		break;
 	}
 	case LSM_AUDIT_DATA_DENTRY: {