Use a case statement instead of if/else

Makes it easy to port packages to other architectures.

pkgs/kernel

@@ -4,11 +4,14 @@ url="$mirror/kernel.tar.gz"
 build: crossmusl
 	cd src/linux-$v
 	cp "$top/stuff/kernel-config-$arch" .config
-	if test "$arch" = "x86_64"; then
+	case "$arch" in
+	x86_64)
 		A=x86_64
-	else
+		;;
+	i486)
 		A=x86
-	fi
+		;;
+	esac
 	make ARCH="$A" bzImage -j$nprocs
 	cp arch/x86/boot/bzImage "$root/boot"
 	cp .config "$root/boot/bzImage.config"

pkgs/mpg123

@@ -3,11 +3,14 @@ url="$mirror/mpg123-$v.tar.bz2"
 
 build: tinyalsa
 	cd src/mpg123-$v
-	if test "$arch" = "x86_64"; then
+	case "$arch" in
+	x86_64)
 		A=x86-64
-	else
+		;;
+	i486)
 		A=x86
-	fi
+		;;
+	esac
 	CC=$CC ./configure --prefix="$root" --with-default-audio=tinyalsa \
 		--enable-static=yes --enable-shared=no --with-cpu="$A"
 	make -j$nprocs

pkgs/tinyxserver

@@ -2,12 +2,15 @@ url="$mirror/tinyxserver.tar.gz"
 
 build: tinyxlib zlib
 	cd src/tinyxserver
-	make clean
-	if test "$arch" = "x86_64"; then
+	case "$arch" in
+	x86_64)
 		EXTRA_CFLAGS="-D_XSERVER64=1 $CFLAGS"
-	else
+		;;
+	i486)
 		EXTRA_CFLAGS="$CFLAGS"
-	fi
+		;;
+	esac
+	make clean
 	make -j$nprocs CC=$CC EXTRA_CFLAGS="$EXTRA_CFLAGS" \
 		FONTDIR="/usr/share/fonts"
 	make DESTDIR="$root" BINDIR="/bin" install