RDMA/hns: Fix memory leak in POE debugfs

driver inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8OLBT



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In the init_poe_ch_debugfs() function, the variable dbgfs can be
directly read without applying for additional memory. Otherwise,
memory leakage may occur.

Fixes: b6643496 ("RDMA/hns: Refactor hns RoCE debugfs")
Signed-off-by: Juan Zhou <zhoujuan51@h-partners.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>