adt-manual: fixed formatting for user-supplied data in example.

(From yocto-docs rev: 0a5b26ab90056b7107bb86329148e8c3a0173065)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/adt-manual/adt-command.xml

@@ -186,7 +186,7 @@
             rebuild it using the appropriate cross-toolchain tools:
             <literallayout class='monospaced'>
      $ ./configure --host=armv5te-poky-linux-gnueabi \
-        --with-libtool-sysroot=<replaceable>sysroot-dir</replaceable>
+        --with-libtool-sysroot=<replaceable>sysroot_dir</replaceable>
             </literallayout>
             <note>
                 If the <filename>configure</filename> script results in problems recognizing the