Commit log 0e0ea8cf5e (uboot-tools: install libubootenv to staging)
mentions that installation is done in <pkg>_INSTALL_STAGING_CMDS directly, but
forgot to remove the now empty UBOOT_TOOLS_INSTALL_LIBUBOOTENV.
Cc: Jörg Krause <joerg.krause@embedded.rocks>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>