Revise iovec_t.__eq__ and vfu_dma_info_t.__eq__ to fix flake8 E721

The newer flake8 version in the arch linux job of the pull request
workflow fails due to:

E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`

Both `__eq__` functions now use `is not` instead of `!=` for the type
initial check.

Signed-off-by: Sandro-Alessio Gierens <sandro@gierens.de>

test/py/libvfio_user.py

@@ -308,7 +308,7 @@ class iovec_t(Structure):
  ]
 
  def __eq__(self, other):
- if type(self) != type(other):
+ if type(self) is not type(other):
  return False
  return self.iov_base == other.iov_base \
  and self.iov_len == other.iov_len
@@ -484,7 +484,7 @@ class vfu_dma_info_t(Structure):
  ]
 
  def __eq__(self, other):
- if type(self) != type(other):
+ if type(self) is not type(other):
  return False
  return self.iova == other.iova \
  and self.vaddr == other.vaddr \