[source] include/cmake.mk: fix host builds

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/?p=source.git;a=commitdiff;h=50e7c1f79d0e72c6f6b63611c5b93fc8be2f70cf

commit 50e7c1f79d0e72c6f6b63611c5b93fc8be2f70cf
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Fri Jul 29 22:47:46 2016 +0200

    include/cmake.mk: fix host builds
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 include/cmake.mk | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/cmake.mk b/include/cmake.mk
index fac2bc0..483a151 100644
--- a/include/cmake.mk
+++ b/include/cmake.mk
@@ -8,6 +8,7 @@ endif
 
 CMAKE_BINARY_DIR = $(PKG_BUILD_DIR)$(if $(CMAKE_BINARY_SUBDIR),/$(CMAKE_BINARY_SUBDIR))
 CMAKE_SOURCE_DIR = $(PKG_BUILD_DIR)
+HOST_CMAKE_SOURCE_DIR = $(HOST_BUILD_DIR)
 MAKE_PATH = $(firstword $(CMAKE_BINARY_SUBDIR) .)
 
 ifeq ($(CONFIG_EXTERNAL_TOOLCHAIN),)
@@ -103,6 +104,6 @@ define Host/Configure/Default
 			-DCMAKE_PREFIX_PATH=$(HOST_BUILD_PREFIX) \
 			-DCMAKE_SKIP_RPATH=TRUE  \
 			$(CMAKE_HOST_OPTIONS) \
-		$(CMAKE_SOURCE_DIR) \
+		$(HOST_CMAKE_SOURCE_DIR) \
 	)
 endef