bitbake: bitbake-user-manual: replace "file name" by "filename"

There are many more instances of "filename" or "filenames" than
of "file name" or "file names".

The winner takes it all!

(Bitbake rev: dcd115176f63256f10db0b24b563683c4bdf8f96)

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

bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst

@@ -1941,7 +1941,7 @@ Wildcard Support in Variables
 =============================
 
 Support for wildcard use in variables varies depending on the context in
-which it is used. For example, some variables and file names allow
+which it is used. For example, some variables and filenames allow
 limited use of wildcards through the "``%``" and "``*``" characters.
 Other variables or names support Python's
 `glob <https://docs.python.org/3/library/glob.html>`_ syntax,

bitbake/doc/bitbake-user-manual/bitbake-user-manual-ref-variables.rst

@@ -339,7 +339,7 @@ overview of their function and contents.
    :term:`BB_LOGFMT`
       Specifies the name of the log files saved into
       ``${``\ :term:`T`\ ``}``. By default, the :term:`BB_LOGFMT`
-      variable is undefined and the log file names get created using the
+      variable is undefined and the log filenames get created using the
       following form::
 
          log.{task}.{pid}
@@ -393,7 +393,7 @@ overview of their function and contents.
    :term:`BB_RUNFMT`
       Specifies the name of the executable script files (i.e. run files)
       saved into ``${``\ :term:`T`\ ``}``. By default, the
-      :term:`BB_RUNFMT` variable is undefined and the run file names get
+      :term:`BB_RUNFMT` variable is undefined and the run filenames get
       created using the following form::
 
          run.{task}.{pid}