kernel: modules: Getting free contributions is not directly related t…

…o the licence

You get free contributions when you mainline your drivers not because
you decide to use the GPL. This is the purpose of the next slide and
this advantage is already listed, so drop the sentence here.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

slides/kernel-source-code-drivers/kernel-source-code-drivers.tex

@@ -164,9 +164,6 @@ \subsection{Linux Code and Device Drivers}
   \begin{itemize}
   \item You don't have to write your driver from scratch. You can
     reuse code from similar free software drivers.
-  \item You could get free community contributions, support, code
-    review and testing, though this generally only happens with code
-    submitted for the mainline kernel.
   \item Your drivers can be freely and easily shipped by others (for
     example by Linux distributions or embedded Linux build systems).
   \item Pre-compiled drivers work with only one kernel version and one