target: Clean up how the dump_mmu() print

The various dump_mmu() take an fprintf()-like callback and a FILE * to
pass to it, and so do their helper functions.  Passing around callback
and argument is rather tiresome.

Most dump_mmu() are called only by the target's hmp_info_tlb().  These
all pass monitor_printf() cast to fprintf_function and the current
monitor cast to FILE *.

SPARC's dump_mmu() gets also called from target/sparc/ldst_helper.c a
few times #ifdef DEBUG_MMU.  These calls pass fprintf() and stdout.

The type-punning is technically undefined behaviour, but works in
practice.  Clean up: drop the callback, and call qemu_printf()
instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-11-armbru@redhat.com>