tracing/uprobes: Check the return value of kstrdup() for tu->filename

tracing/uprobes: Check the return value of kstrdup() for tu->filename

[ Upstream commit 8c7224245557707c613f130431cafbaaa4889615 ]

kstrdup() returns NULL when some internal memory errors happen, it is
better to check the return value of it so to catch the memory error in
time.

Link: https://lkml.kernel.org/r/tencent_3C2E330722056D7891D2C83F29C802734B06@qq.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>