tracing: Fix white space issues in parse_pred() function

Trivial fix to clean up an indentation issue, a whole chunk of code
has an extra space in the indentation.

Link: http://lkml.kernel.org/r/20181109132312.20994-1-colin.king@canonical.comSigned-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>