Driver core: make bus_find_device_by_name() more robust

Use sysfs_streq() in bus_find_device_by_name() so trailing newlines
are ignored (E.G. in bind/unbind).

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>