Use git HTTP URLs without /p in it

Change-Id: I9972b138c6dd2a289880c4ec8b3fe64fc3baa66b
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-on: https://review.coreboot.org/25545
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

Documentation/corebootBuildingGuide.tex

@@ -116,7 +116,7 @@ The latest coreboot sources are available via GIT.
 For users who doesn't need to change and commit the code:
 { \small
 \begin{verbatim}
-$ git clone https://review.coreboot.org/p/coreboot
+$ git clone https://review.coreboot.org/coreboot
 \end{verbatim}
 }
 For developers, you need to get a gerrit account which you can register