coredump: fix handling of num_pages

This patch fixes the following error:

$ sudo make -C test/others/criu-coredump run
...
Traceback (most recent call last):
  File "/home/circleci/criu/coredump/coredump", line 55, in <module>
    main()
  File "/home/circleci/criu/coredump/coredump", line 47, in main
    coredump(opts)
  File "/home/circleci/criu/coredump/coredump", line 14, in coredump
    cores = generator(os.path.realpath(opts['in']))
  File "/home/circleci/criu/coredump/criu_coredump/coredump.py", line 192, in __call__
    self.coredumps[pid] = self._gen_coredump(pid)
  File "/home/circleci/criu/coredump/criu_coredump/coredump.py", line 214, in _gen_coredump
    cd.vmas = self._gen_vmas(pid)
  File "/home/circleci/criu/coredump/criu_coredump/coredump.py", line 992, in _gen_vmas
    v.data = self._gen_mem_chunk(pid, vma, v.filesz)
  File "/home/circleci/criu/coredump/criu_coredump/coredump.py", line 879, in _gen_mem_chunk
    page_mem = self._get_page(pid, page_no)
  File "/home/circleci/criu/coredump/criu_coredump/coredump.py", line 797, in _get_page
    num_pages = m.get("nr_pages", m.compat_nr_pages)
AttributeError: 'dict' object has no attribute 'compat_nr_pages'
+ exit 1
make[1]: *** [Makefile:3: run] Error 1

Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
Signed-off-by: Andrei Vagin <avagin@google.com>

Author: rst0git

coredump/criu_coredump/coredump.py

@@ -794,7 +794,8 @@ def _get_page(self, pid, page_no):
         off = 0  # in pages
         for m in pagemap[1:]:
             found = False
-            num_pages = m.get("nr_pages", m.compat_nr_pages)
+            num_pages = m.get("nr_pages", m["compat_nr_pages"])
+
             for i in range(num_pages):
                 if m["vaddr"] + i * PAGESIZE == page_no * PAGESIZE:
                     found = True