docs/manual: fix typo

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit e10e4d19e3c02a9d251499172a65c77c59e15a67)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

docs/manual/using-buildroot-development.txt

@@ -50,11 +50,11 @@ BUSYBOX_OVERRIDE_SRCDIR = /home/bob/busybox/
 When Buildroot finds that for a given package, an
 +<pkg>_OVERRIDE_SRCDIR+ has been defined, it will no longer attempt to
 download, extract and patch the package. Instead, it will directly use
-the source code available in in the specified directory and +make
-clean+ will not touch this directory. This allows to point Buildroot
-to your own directories, that can be managed by Git, Subversion, or
-any other version control system. To achieve this, Buildroot will use
-_rsync_ to copy the source code of the component from the specified
+the source code available in the specified directory and +make clean+
+will not touch this directory. This allows to point Buildroot to your
+own directories, that can be managed by Git, Subversion, or any other
+version control system. To achieve this, Buildroot will use _rsync_ to
+copy the source code of the component from the specified
 +<pkg>_OVERRIDE_SRCDIR+ to +output/build/<package>-custom/+.
 
 This mechanism is best used in conjunction with the +make