exec: round up size on MR resize

Block size must fundamentally be a multiple of target page size.
Aligning automatically removes need to worry about the alignment
from callers.

Note: the only caller of qemu_ram_resize (acpi) already happens to have
size padded to a power of 2, but we would like to drop the padding in
ACPI core, and don't want to expose target page size knowledge to ACPI.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Paolo Bonzini <ponzini@redhat.com>

exec.c

@@ -1347,6 +1347,8 @@ int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp)
 
     assert(block);
 
+    newsize = TARGET_PAGE_ALIGN(newsize);
+
     if (block->used_length == newsize) {
         return 0;
     }