libtraceevent: Fix build with binutils 2.35

In binutils 2.35, 'nm -D' changed to show symbol versions along with
symbol names, with the usual @@ separator.  When generating
libtraceevent-dynamic-list we need just the names, so strip off the
version suffix if present.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-trace-devel@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/plugins/Makefile

@@ -197,7 +197,7 @@ define do_generate_dynamic_list_file
 	xargs echo "U w W" | tr 'w ' 'W\n' | sort -u | xargs echo`;\
 	if [ "$$symbol_type" = "U W" ];then				\
 		(echo '{';                                              \
-		$(NM) -u -D $1 | awk 'NF>1 {print "\t"$$2";"}' | sort -u;\
+		$(NM) -u -D $1 | awk 'NF>1 {sub("@.*", "", $$2); print "\t"$$2";"}' | sort -u;\
 		echo '};';                                              \
 		) > $2;                                                 \
 	else                                                            \