Quote $TERMUX_ARCH when used in toplevel script

packages/libmpfr/build.sh

@@ -5,7 +5,7 @@ TERMUX_PKG_VERSION=4.0.1
 TERMUX_PKG_SRCURL=https://mirrors.kernel.org/gnu/mpfr/mpfr-${TERMUX_PKG_VERSION}.tar.xz
 TERMUX_PKG_SHA256=67874a60826303ee2fb6affc6dc0ddd3e749e9bfcb4c8655e3953d0458a6e16e
 TERMUX_PKG_EXTRA_CONFIGURE_ARGS="ac_cv_header_locale_h=no"
-if [ $TERMUX_ARCH = i686 ]; then
+if [ "$TERMUX_ARCH" = i686 ]; then
 	# Avoid clang bug with NDK r16:
 	TERMUX_PKG_CLANG=no
 fi

packages/openssl/build.sh

@@ -11,7 +11,7 @@ TERMUX_PKG_BUILD_IN_SRC=yes
 # https://github.com/android-ndk/ndk/issues/144
 # https://github.com/openssl/openssl/issues/1498
 # May be fixed in later openssl version.
-if [ $TERMUX_ARCH = arm ]; then
+if [ "$TERMUX_ARCH" = arm ]; then
 	TERMUX_PKG_CLANG=no
 fi