tracing: Remove duplicate warnings when calling trace_create_file()

Since the same warning message is already printed in the
trace_create_file() function, there is no need to print it again.

Link: https://lkml.kernel.org/r/20220109162232.361747-1-ytcoode@gmail.com



Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>