delete duplicate variable definition

CALLED_FROM_SETUP and BUILD_SYSTEM set in get_build_var before make execution
no need to set them before calling get_build_var function

Change-Id: Ia79e11e5e3aa5c7fd337b989c16d50750b6c1442
Signed-off-by: Andrey Belous <belous.andrey@gmail.com>

envsetup.sh

@@ -58,7 +58,6 @@ function check_product()
         echo "Couldn't locate the top of the tree.  Try setting TOP." >&2
         return
     fi
-    CALLED_FROM_SETUP=true BUILD_SYSTEM=build/core \
         TARGET_PRODUCT=$1 \
         TARGET_BUILD_VARIANT= \
         TARGET_BUILD_TYPE= \