verify.h was added without include guards. This means compiling anything
including both include/grub/verify.h and include/grub/lib/cmdline.h fails
(at least grub-core/loader/arm64/linux.c.
Add the necessary include guard.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
a5d865a039