kconfig: qconf: refactor ConfigInfoView::clicked()

Most of the code in ConfigInfoView::clicked() is unnecessary.
There is no need to use the regular expression to search for a symbol.
Calling sym_find() is simpler and faster.

The hyperlink always begins with the "s" tag, and there is no other
tag used. Remove it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>