e2fsprogs: fix type-punning warnings

e2fsprogs: fix type-punning warnings

Flags used during RHEL/Fedora builds lead to a couple type-punning
warnings:

  recovery.c: In function 'do_one_pass':
  recovery.c:539: warning: dereferencing type-punned pointer will break strict-aliasing rules
  ./csum.c: In function 'print_csum':
  ./csum.c:170: warning: dereferencing type-punned pointer will break strict-aliasing rules

The two changes below fix this up.

Note that the csum test binary output changes slightly, but this does
not break any tests.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>