loader: Drop argv[] argument in grub_initrd_load()

loader: Drop argv[] argument in grub_initrd_load()

In the case of an error grub_initrd_load() uses argv[] to print the
filename that caused the error. It is also possible to obtain the
filename from the file handles and there is no need to duplicate that
information in argv[], so let's drop it.

Signed-off-by: Nikita Ermakov <arei@altlinux.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>