Get rid of unused variables

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

Makefile

@@ -268,13 +268,6 @@ STAMP_DIR:=$(BASE_DIR)/stamps
 BINARIES_DIR:=$(BASE_DIR)/images
 TARGET_DIR:=$(BASE_DIR)/target
 
-# define values for prepatched source trees for toolchains
-VENDOR_SITE:=$(call qstrip,$(BR2_VENDOR_SITE))
-VENDOR_BINUTILS_RELEASE:=$(call qstrip,$(BR2_VENDOR_BINUTILS_RELEASE))
-VENDOR_GCC_RELEASE:=$(call qstrip,$(BR2_VENDOR_GCC_RELEASE))
-VENDOR_UCLIBC_RELEASE:=$(call qstrip,$(BR2_VENDOR_UCLIBC_RELEASE))
-VENDOR_PATCH_DIR:=$(call qstrip,$(BR2_VENDOR_PATCH_DIR))
-
 BR2_DEPENDS_DIR=$(BUILD_DIR)/buildroot-config
 
 include toolchain/Makefile.in