migration: Unexport ram_mig_init()

It's only used within migration/.

Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20241024213056.1395400-4-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>

include/migration/misc.h

@@ -39,7 +39,6 @@ void precopy_add_notifier(NotifierWithReturn *n);
 void precopy_remove_notifier(NotifierWithReturn *n);
 int precopy_notify(PrecopyNotifyReason reason, Error **errp);
 
-void ram_mig_init(void);
 void qemu_guest_free_page_hint(void *addr, size_t len);
 bool migrate_ram_is_ignored(RAMBlock *block);
 

migration/ram.h

@@ -44,6 +44,7 @@ extern XBZRLECacheStats xbzrle_counters;
     INTERNAL_RAMBLOCK_FOREACH(block)                   \
         if (!qemu_ram_is_migratable(block)) {} else
 
+void ram_mig_init(void);
 int xbzrle_cache_resize(uint64_t new_size, Error **errp);
 uint64_t ram_bytes_remaining(void);
 uint64_t ram_bytes_total(void);