But the loop in reset_ftrace_filter will try to remove multiple instances
multiple times. If this happens the second time will error and cause the
test to fail.
At each iteration of the loop, check to see if the probe being removed still
exists.
Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>