common CHANGE optimize ly_strequal()
common CHANGE optimize ly_strequal()

Avoid -Waddress compiler warning when comparing static string. Also
can do some optimization in compile time (probably already done
anyway, so the real reason is to avoid the warning).

lukasmacko/libyang,lukasmacko/libyang,PavolVican/libyang,PavolVican/libyang,PavolVican/libyang,PavolVican/libyang,PavolVican/libyang