manuals: code insertion simplification over two lines

This simplifies paragraphs ending with a colon and followed
by code insertion.

Automatically substituted through the command:
sed -i -z "s/:\n\s*::/::/g" file.rst

This generates identical HTML output.

(From yocto-docs rev: 28e2192a7c12d64b68061138a9f6c796453eebb1)

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

documentation/ref-manual/qa-checks.rst

@@ -221,8 +221,7 @@ Errors and Warnings
    Typically, the way to solve this performance issue is to add "-fPIC"
    or "-fpic" to the compiler command-line options. For example, given
    software that reads :term:`CFLAGS` when you build it,
-   you could add the following to your recipe:
-   ::
+   you could add the following to your recipe::
 
       CFLAGS_append = " -fPIC "
 
@@ -240,8 +239,7 @@ Errors and Warnings
    variable is being passed to the linker command. A common workaround
    for this situation is to pass in ``LDFLAGS`` using
    :term:`TARGET_CC_ARCH` within the recipe as
-   follows:
-   ::
+   follows::
 
       TARGET_CC_ARCH += "${LDFLAGS}"
 
@@ -265,8 +263,7 @@ Errors and Warnings
 
    The ``/usr/share/info/dir`` should not be packaged. Add the following
    line to your :ref:`ref-tasks-install` task or to your
-   ``do_install_append`` within the recipe as follows:
-   ::
+   ``do_install_append`` within the recipe as follows::
 
       rm ${D}${infodir}/dir