docs/buildroot.html: fix minor typo

STAGING_DIR is output/staging, not build/staging per default.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

docs/buildroot.html

@@ -702,7 +702,7 @@ endif
      might be cumbersome.</p>
 
      <p>It is also possible to generate the Buildroot toolchain in
-     another directory than <code>build/staging</code> using the
+     another directory than <code>output/staging</code> using the
      <code>Build options -&gt; Toolchain and header file
      location</code> option. This could be useful if the toolchain
      must be shared with other users.</p>