Embedded Linux: use output/host/bin instead of output/host/usr/bin/

For simplicity and consistency with what's already done
in the debugging lab.

/output/host/usr is actually a link to /output/host

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>

labs/sysdev-application-development/sysdev-application-development.tex

@@ -16,15 +16,15 @@ \section{Compile your own application}
 integrate this simple application to our Linux system.
 
 Buildroot has generated toolchain wrappers in
-\code{output/host/usr/bin}, which make it easier to use the toolchain,
+\code{output/host/bin}, which make it easier to use the toolchain,
 since these wrappers pass some mandatory flags (especially the
 \code{--sysroot} {\em gcc} flag, which tells {\em gcc} where to look
 for the headers and libraries).
 
 Let's add this directory to our \code{PATH}:
 
 \begin{bashinput}
-$ export PATH=$HOME/__SESSION_NAME__-labs/buildroot/buildroot-2021.08.X/output/host/usr/bin:$PATH
+$ export PATH=$HOME/__SESSION_NAME__-labs/buildroot/buildroot-2021.08.X/output/host/bin:$PATH
 \end{bashinput}
 \normalsize
 
@@ -37,7 +37,7 @@ \section{Compile your own application}
 libraries. So let's use \code{pkg-config} to query the {\em
 pkg-config} database about the location of the header files and the
 list of libraries needed to build an application against
-{\em ncurses}\footnote{Again, \code{output/host/usr/bin} has a special
+{\em ncurses}\footnote{Again, \code{output/host/bin} has a special
 \code{pkg-config} that automatically knows where to look, so it
 already knows the right paths to find \code{.pc} files and their
 sysroot.}:

labs/sysdev-real-time/sysdev-real-time.tex

@@ -125,7 +125,7 @@ \subsection{Measure the effect of high-resolution timers}
 
 %\simall
 \begin{bashinput}
-$ export PATH=$HOME/__SESSION_NAME__-labs/realtime/buildroot-2021.02.X/output/host/usr/bin:$PATH
+$ export PATH=$HOME/__SESSION_NAME__-labs/realtime/buildroot-2021.02.X/output/host/bin:$PATH
 \end{bashinput}
 \normalsize
 
@@ -265,7 +265,7 @@ \subsection{Testing Xenomai latencies}
 %\small
 \begin{bashinput}
 $ cd $HOME/__SESSION_NAME__-labs/realtime/nfsroot/root
-$ export PATH=$HOME/__SESSION_NAME__-labs/realtime/buildroot-2021.02.X/output/host/usr/bin:$PATH
+$ export PATH=$HOME/__SESSION_NAME__-labs/realtime/buildroot-2021.02.X/output/host/bin:$PATH
 $ arm-linux-gnueabihf-gcc -o rttest rttest.c \
     $(DESTDIR=../../buildroot-2021.02.X/output/staging/ \
     ../../buildroot-2021.02.X/output/staging/usr/bin/xeno-config \