[man] Fix order of depot_tools in PATH

For development in V8, and I guess also in Chrome, it is important that
depot_tools are at the beginning of $PATH. This was explicitly mentioned
in the original tutorial. However, it seems like a cleanup CL changed
this recently, see https://crrev.com/c/1593820. This CL changes the
order in $PATH back to the original order.

CC=marja@chromium.org, dmcardle@chromium.org
R=iannucci@chromium.org

Change-Id: Idaed3ada05cddd666734c03a25503fe5dc481e3a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2124657
Auto-Submit: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>

man/man7/depot_tools_tutorial.7

@@ -222,13 +222,13 @@ Clone the \fIdepot_tools\fR repository:
 .\}
 .sp
 .sp
-Add \fIdepot_tools\fR to the \fIend\fR of your PATH (you will probably want to put this in your ~/\&.bashrc or ~/\&.zshrc)\&. Assuming you cloned \fIdepot_tools\fR to /path/to/depot_tools:
+Add \fIdepot_tools\fR to the \fIfront\fR of your PATH (you will probably want to put this in your ~/\&.bashrc or ~/\&.zshrc)\&. Assuming you cloned \fIdepot_tools\fR to /path/to/depot_tools:
 .sp
 .if n \{\
 .RS 4
 .\}
 .nf
-\fB$ export PATH=$PATH:/path/to/depot_tools\fR
+\fB$ export PATH=/path/to/depot_tools:$PATH\fR
 .fi
 .if n \{\
 .RE

man/src/depot_tools_tutorial.txt

@@ -74,13 +74,13 @@ Clone the 'depot_tools' repository:
 [white]**$ git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git**
 ----
 
-Add 'depot_tools' to the 'end' of your PATH (you will probably want to put this
+Add 'depot_tools' to the 'front' of your PATH (you will probably want to put this
 in your `~/.bashrc` or `~/.zshrc`). Assuming you cloned 'depot_tools' to
 `/path/to/depot_tools`:
 
 [postsubs="quotes"]
 ----
-[white]**$ export PATH=$PATH:/path/to/depot_tools**
+[white]**$ export PATH=/path/to/depot_tools:$PATH**
 ----
 
 // No need to show the Windows stuff on the manpage output.