tools lib traceevent: Install trace-seq.h API header file

This patch installs trace-seq.h header file on "make install".
Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20181130154647.176265533@goodmis.orgSigned-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/Makefile

@@ -285,7 +285,7 @@ define do_install_pkgconfig_file
 	fi
 endef
 
-install_lib: all_cmd install_plugins install_pkgconfig
+install_lib: all_cmd install_plugins install_headers install_pkgconfig
 	$(call QUIET_INSTALL, $(LIB_TARGET)) \
 		$(call do_install_mkdir,$(libdir_SQ)); \
 		cp -fpR $(LIB_INSTALL) $(DESTDIR)$(libdir_SQ)
@@ -302,6 +302,7 @@ install_headers:
 	$(call QUIET_INSTALL, headers) \
 		$(call do_install,event-parse.h,$(prefix)/include/traceevent,644); \
 		$(call do_install,event-utils.h,$(prefix)/include/traceevent,644); \
+		$(call do_install,trace-seq.h,$(prefix)/include/traceevent,644); \
 		$(call do_install,kbuffer.h,$(prefix)/include/traceevent,644)
 
 install: install_lib