[OE-core] [PATCH] cmake.bbclass: use weakest ??= assignment for default OECMAKE_SOURCEPATH

[Andre McCurdy]

Make it slightly easier to support situations where the default path
needs to be over-ridden more than once.

Signed-off-by: Andre McCurdy <armccurdy at gmail.com>
---
 meta/classes/cmake.bbclass | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meta/classes/cmake.bbclass b/meta/classes/cmake.bbclass
index 3f67091..f58ad78 100644
--- a/meta/classes/cmake.bbclass
+++ b/meta/classes/cmake.bbclass
@@ -1,5 +1,5 @@
 # Path to the CMake file to process.
-OECMAKE_SOURCEPATH ?= "${S}"
+OECMAKE_SOURCEPATH ??= "${S}"
 
 DEPENDS_prepend = "cmake-native "
 B = "${WORKDIR}/build"
-- 
1.9.1