selftest: ftrace: Fix to pick text symbols for kprobes

Fix to pick text symbols for multiple kprobe testcase.
kallsyms shows text symbols with " t " or " T " but
current testcase picks all symbols including "t",
so it picks data symbols if it includes 't' (e.g. "str").

This fixes it to find symbol lines with " t " or " T "
(including spaces).
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Russell King <linux@armlinux.org.uk>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc

@@ -12,8 +12,8 @@ case `uname -m` in
   *) OFFS=0;;
 esac
 
-echo "Setup up to 256 kprobes"
-grep t /proc/kallsyms | cut -f3 -d" " | grep -v .*\\..* | \
+echo "Setup up kprobes on first 256 text symbols"
+grep -i " t " /proc/kallsyms | cut -f3 -d" " | grep -v .*\\..* | \
 head -n 256 | while read i; do echo p ${i}+${OFFS} ; done > kprobe_events ||:
 
 echo 1 > events/kprobes/enable