UNIC: Add the processing of the return value of ubl_rmv_sw_ctype.

driver inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8GIXF


CVE: NA

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After sw_ctype fails to be removed, the xmit process is
terminated.

Signed-off-by: Haibin Lu <luhaibin10@hisilicon.com>