mesa: assign S in include file

Anything including mesa.inc will have the sources extracted in
${UNPACKDIR}/mesa-${PV}.

The default for S is ${UNPACKDIR}/${BP}. ${BP} is ${BPN}-${PV}. Because
mesa.bb is named mesa, BPN will be mesa and thus S wasn't required for
mesa.bb but only for mesa-gl.bb. This also explains why this change is
fine for mesa.bb as the value of S won't have changed, the ${BPN} part
is now just hardcoded to "mesa" for mesa.bb instead.

No intended change in behavior.

(From OE-Core rev: a77c0f5919fbef6e076d2b085f71c8bbbfc9188a)

Signed-off-by: Ross Burton <ross.burton@arm.com>
[added commit log and title]
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-graphics/mesa/mesa-gl.bb

@@ -4,8 +4,6 @@ SUMMARY += " (OpenGL only, no EGL/GLES)"
 
 PROVIDES = "virtual/libgl virtual/mesa"
 
-S = "${UNPACKDIR}/mesa-${PV}"
-
 TARGET_CFLAGS = "-I${STAGING_INCDIR}/drm"
 
 # At least one DRI rendering engine is required to build mesa.

meta/recipes-graphics/mesa/mesa.inc

@@ -24,6 +24,8 @@ PV = "25.2.0"
 
 UPSTREAM_CHECK_GITTAGREGEX = "mesa-(?P<pver>\d+(\.\d+)+)"
 
+S = "${UNPACKDIR}/mesa-${PV}"
+
 #because we cannot rely on the fact that all apps will use pkgconfig,
 #make eglplatform.h independent of MESA_EGL_NO_X11_HEADER
 do_install:append() {