doc: convert \--option to --option

Rather than using a backslash in \--foo, with or without ''-quoting,
write `--foo` for better rendering. As explained in commit 1c262bb7b
(doc: convert \--option to --option, 2015-05-13), the backslash is not
needed for the versions of AsciiDoc that we support, but is rendered
literally by Asciidoctor.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>

Documentation/git-format-patch.txt

@@ -47,7 +47,7 @@ There are two ways to specify which commits to operate on.
 
 The first rule takes precedence in the case of a single <commit>.  To
 apply the second rule, i.e., format everything since the beginning of
-history up until <commit>, use the '\--root' option: `git format-patch
+history up until <commit>, use the `--root` option: `git format-patch
 --root <commit>`.  If you want to format only <commit> itself, you
 can do this with `git format-patch -1 <commit>`.
 

Documentation/git-push.txt

@@ -300,7 +300,7 @@ origin +master` to force a push to the `master` branch). See the
 	These options are passed to linkgit:git-send-pack[1]. A thin transfer
 	significantly reduces the amount of sent data when the sender and
 	receiver share many of the same objects in common. The default is
-	\--thin.
+	`--thin`.
 
 -q::
 --quiet::