selftests/ftrace: Add more tests for removing of function probes

Al Viro discovered a bug in the removing of function probes where if it had
a '*' at the beginning, it would fail to find any matches. That is, because
it reset the glob search string to the the initial string with a "MATCH_END"
type, instead of skipping the wildcard "*" it included it, where it would
not match any functions because "*" was being treated as a normal character
and not a wildcard one.

Link: http://lkml.kernel.org/r/20180127031706.GE13338@ZenIV.linux.org.uk



Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>