manuals: fix suspicious newlines

- That could originate from documentation migration issues
- Checked that the corresponding links still exist

(From yocto-docs rev: 38bae8f6067bc12f3617ed38587737d22dd7b32c)

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/variables.rst

@@ -768,9 +768,7 @@ system and gives an overview of their function and contents.
       .. note::
 
          If you run BitBake from a directory outside of the
-         Build Directory
-         , you must be sure to set
-         BBPATH
+         :term:`Build Directory`, you must be sure to set ``BBPATH``
          to point to the Build Directory. Set the variable as you would any
          environment variable and then run BitBake:
          ::