perf unwind: Set userdata for all __report_module() paths

When locating the DWARF module for a given address, __find_debuginfo()
requires a 'struct dso' passed via the userdata argument.

However, this field is only set in __report_module() if the module is
found in via dwfl_addrmodule(), not if it is found later via
dwfl_report_elf().

Set userdata irrespective of how the DWARF module was found, as long as
we found a module.

Fixes: bf53fc6b

 ("perf unwind: Fix separate debug info files when using elfutils' libdw's unwinder")
Signed-off-by: Dave Rigby <d.rigby@me.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211801
Acked-by: Jan Kratochvil <jan.kratochvil@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/linux-perf-users/20210218165654.36604-1-d.rigby@me.com/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>