util: avoid a name-error warning in the `mmapread` exception handler...
util: avoid a name-error warning in the `mmapread` exception handler
Newly caught by pytype 2021-09-09.
File "/mnt/c/Users/Matt/hg/mercurial/util.py", line 458, in mmapread: Name 'fd' is not defined [name-error]
Differential Revision:
https://phab.mercurial-scm.org/D11470