trace-cmd: Remove obsolete tep_set_local_bigendian() call

The tep_set_local_bigendian() call in tracecmd_alloc_fd() is obsolete
because tep_alloc() already initializes the host endianness. This was
a legacy from commit cd001f7b40f9d ("Add handler to pevent functions")
when pevent_alloc() did not initialize host_bigendian.

The removal has been functionally tested by recording a trace on an
x86 (little-endian) host and successfully reporting it on an s390x
(big-endian) virtual machine, confirming endianness conversion works
correctly without this line.

Link: https://lore.kernel.org/20251227140910.2024-1-huowenjun.dev@gmail.com
Signed-off-by: Wenjun Huo <huowenjun.dev@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>