xen/arm: mm: Remove ; at the end of mm_printk()

xen/arm: mm: Remove ; at the end of mm_printk()

The ; at the end of mm_printk() means the following code will not build
correctly:

if ( ... )
    mm_printk(...);
else
    ...

As we treat the macro as a function, we want to remove the ; at the end
of it.

Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>