The invocation instructions for the copy-libev example are a bit too wide.
The obvious wrapping

  ./copy-ev \
    nbd+unix:///?socket=/tmp/src.sock \
    nbd+unix:///?socket=/tmp/dst.sock

is not desirable in a C-language comment, because the C standard places
line splicing before comment squashing (translation phases #2 and #3,
respectively). Therefore use shell variables.

While at it, fix a small typo (from commit 6be6a902, "examples: Add
example for integrating with libev", 2021-03-01): the executable is called
"copy-libev", not "copy-ev".

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2172516


Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20230418172631.485472-2-lersek@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>