SUNRPC: svc_tcp_sendmsg() should handle errors from xdr_alloc_bvec()

stable inclusion
from stable-v5.10.111
commit b3c00be2ff8bc7e211fb04ec42facf0e4c876800
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5GL1Z

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b3c00be2ff8bc7e211fb04ec42facf0e4c876800



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[ Upstream commit b056fa07 ]

The allocation is done with GFP_KERNEL, but it could still fail in a low
memory situation.

Fixes: 4a85a6a3 ("SUNRPC: Handle TCP socket sends with kernel_sendpage() again")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>