[openwrt/openwrt] scripts/mkits.sh: add missing quotes

[LEDE Commits]

ynezz pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/765858f7ad77d1c88ad2b0f6f01839db105a1e36

commit 765858f7ad77d1c88ad2b0f6f01839db105a1e36
Author: Rosen Penev <rosenp at gmail.com>
AuthorDate: Sun Jan 5 18:31:18 2020 -0800

    scripts/mkits.sh: add missing quotes
    
    Found with shellcheck.
    
    Signed-off-by: Rosen Penev <rosenp at gmail.com>
---
 scripts/mkits.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/mkits.sh b/scripts/mkits.sh
index def3d3c7c2..53b9ec5f20 100755
--- a/scripts/mkits.sh
+++ b/scripts/mkits.sh
@@ -55,7 +55,7 @@ if [ -z "${ARCH}" ] || [ -z "${COMPRESS}" ] || [ -z "${LOAD_ADDR}" ] || \
 	usage
 fi
 
-ARCH_UPPER=$(echo $ARCH | tr '[:lower:]' '[:upper:]')
+ARCH_UPPER=$(echo "$ARCH" | tr '[:lower:]' '[:upper:]')
 
 # Conditionally create fdt information
 if [ -n "${DTB}" ]; then
@@ -115,4 +115,4 @@ ${FDT_NODE}
 };"
 
 # Write .its file to disk
-echo "$DATA" > ${OUTPUT}
+echo "$DATA" > "${OUTPUT}"