perf test shell probe_vfs_getname: Remove extraneous '=' from probe line number regex

Thomas reported the vfs_getname perf tests failing on s/390, it seems it
was just to some extraneous '=' somehow getting into the regexp, remove
it, now:

  root@x1:~# perf test getname
   91: Add vfs_getname probe to get syscall args filenames             : Ok
   93: Use vfs_getname probe to get syscall args filenames             : FAILED!
  126: Check open filename arg using perf trace + vfs_getname          : Ok
  root@x1:~#

Second one remains a mistery, have to take some time to nail it down.
Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>,
Link: https://lore.kernel.org/lkml/1d7f3b7b-9edc-4d90-955c-9345428563f1@linux.ibm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/lib/probe_vfs_getname.sh

@@ -14,10 +14,10 @@ add_probe_vfs_getname() {
 	add_probe_verbose=$1
 	if [ $had_vfs_getname -eq 1 ] ; then
 		result_filename_re="[[:space:]]+([[:digit:]]+)[[:space:]]+result->uptr.*"
-		line=$(perf probe -L getname_flags 2>&1 | grep -E "$result_filename_re=" | sed -r "s/$result_filename_re=/\1/")
+		line=$(perf probe -L getname_flags 2>&1 | grep -E "$result_filename_re" | sed -r "s/$result_filename_re/\1/")
 		if [ -z "$line" ] ; then
 			result_aname_re="[[:space:]]+([[:digit:]]+)[[:space:]]+result->aname = NULL;"
-			line=$(perf probe -L getname_flags 2>&1 | grep -E "$result_aname_re=" | sed -r "s/$result_aname_re=/\1/")
+			line=$(perf probe -L getname_flags 2>&1 | grep -E "$result_aname_re" | sed -r "s/$result_aname_re/\1/")
 		fi
 		perf probe -q       "vfs_getname=getname_flags:${line} pathname=result->name:string" || \
 		perf probe $add_probe_verbose "vfs_getname=getname_flags:${line} pathname=filename:ustring"