Fix more instances of `which`

How did I miss this before?

disabled-packages/rustc-nightly/build.sh

@@ -26,8 +26,8 @@ termux_step_configure () {
 			-e "s|@TERMUX_PREFIX@|$TERMUX_PREFIX|g" \
 			-e "s|@TERMUX_HOST_PLATFORM@|$TERMUX_HOST_PLATFORM|g" \
 			-e "s|@RUST_TARGET_TRIPLE@|$CARGO_TARGET_NAME|g" \
-			-e "s|@CARGO@|$(which cargo)|g" \
-			-e "s|@RUSTC@|$(which rustc)|g" > $TERMUX_PKG_BUILDDIR/config.toml
+			-e "s|@CARGO@|$(command -v cargo)|g" \
+			-e "s|@RUSTC@|$(command -v rustc)|g" > $TERMUX_PKG_BUILDDIR/config.toml
 
 	export X86_64_UNKNOWN_LINUX_GNU_OPENSSL_LIB_DIR=/usr/lib/x86_64-linux-gnu
 	export X86_64_UNKNOWN_LINUX_GNU_OPENSSL_INCLUDE_DIR=/usr/include

scripts/build/termux_step_setup_toolchain.sh

@@ -163,7 +163,7 @@ termux_setup_standalone_toolchain() {
 	# Create a pkg-config wrapper. We use path to host pkg-config to
 	# avoid picking up a cross-compiled pkg-config later on.
 	local _HOST_PKGCONFIG
-	_HOST_PKGCONFIG=$(which pkg-config)
+	_HOST_PKGCONFIG=$(command -v pkg-config)
 	mkdir -p "$PKG_CONFIG_LIBDIR"
 	cat > $_TERMUX_TOOLCHAIN_TMPDIR/bin/pkg-config <<-HERE
 		#!/bin/sh