mem: Use long for memory size

When checkpointing applications with really big
memory slab (like in our vz7 test with 920G of
memory) the int type get cutted, we should use
long int instead, just like we do in other code
pieces.

Otherwise get (on vz7's criu, which s sharing the code)

 | pie: 756: Daemon waits for command
 | (01.193097) Wait for ack 12 on daemon socket
 | (01.193112) Fetched ack: 12 12 0
 | (01.193164) 988065 fdinfo 0: pos:                0 flags:           100002/0
 | (01.193201) fdinfo: type: 0xb flags: 0100002/0 pos:        0 fd: 0
 | (01.193279) 988065 fdinfo 1: pos:                0 flags:           100002/0
 | (01.193307) fdinfo: type: 0xb flags: 0100002/0 pos:        0 fd: 1
 | (01.193341) 988065 fdinfo 2: pos:                0 flags:           100002/0
 | (01.193365) fdinfo: type: 0xb flags: 0100002/0 pos:        0 fd: 2
 | (01.193375) ----------------------------------------
 | (01.193405) Error (criu/parasite-syscall.c:243): BUG at criu/parasite-syscall.c:243
 | pie: 756: Error (criu/pie/parasite.c:676): Trimmed message received (1>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/include/mem.h

@@ -17,7 +17,7 @@ struct mem_dump_ctl {
 extern bool page_in_parent(bool dirty);
 extern int prepare_mm_pid(struct pstree_item *i);
 extern int do_task_reset_dirty_track(int pid);
-extern unsigned int dump_pages_args_size(struct vm_area_list *vmas);
+extern unsigned long dump_pages_args_size(struct vm_area_list *vmas);
 extern int parasite_dump_pages_seized(struct pstree_item *item,
 				      struct vm_area_list *vma_area_list,
 				      struct mem_dump_ctl *mdc,

criu/mem.c

@@ -72,7 +72,7 @@ int do_task_reset_dirty_track(int pid)
        return ret;
 }
 
-unsigned int dump_pages_args_size(struct vm_area_list *vmas)
+unsigned long dump_pages_args_size(struct vm_area_list *vmas)
 {
 	/* In the worst case I need one iovec for each page */
 	return sizeof(struct parasite_dump_pages_args) +