extract_utils: extract(): rename ARGS variable to SPEC_ARGS

* This is a cleanup patch.

Change-Id: I2a4aac840c06c4f9b94b77b32ead33352ce395ff
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
diff --git a/build/tools/extract_utils.sh b/build/tools/extract_utils.sh
index cf71f0b..4e72b3e 100644
--- a/build/tools/extract_utils.sh
+++ b/build/tools/extract_utils.sh
@@ -984,12 +984,12 @@
 
         local SPEC_SRC_FILE=$(src_file "${FILELIST[$i-1]}")
         local SPEC_DST_FILE=$(target_file "${FILELIST[$i-1]}")
-        local ARGS=$(target_args "${FILELIST[$i-1]}")
+        local SPEC_ARGS=$(target_args "${FILELIST[$i-1]}")
         local OUTPUT_DIR="$OUTPUT_ROOT"
         local TMP_DIR="$OUTPUT_TMP"
         local TARGET=
 
-        if [ "$ARGS" = "rootfs" ]; then
+        if [ "${SPEC_ARGS}" = "rootfs" ]; then
             TARGET="${SPEC_DST_FILE}"
             OUTPUT_DIR="$OUTPUT_DIR/rootfs"
             TMP_DIR="$TMP_DIR/rootfs"