lsinitrd.sh: prevent < <$() construct

Running dracut in a chroot environment, which has /dev not correctly
setup will result in errors like:

/usr/bin/lsinitrd: line 164: /dev/fd/62: No such file or directory
cpio: Malformed number �5�OK��
cpio: Malformed number 5�OK��
cpio: Malformed number �OK��

This is because bash wants /dev/fd/<num> for constructs like:
foo < <$(bar)

lsinitrd.sh

@@ -160,27 +160,35 @@ case $bin in
         ;;
 esac
 
-if [[ $SKIP ]]; then
-    read -N 6 bin < <($SKIP "$image")
-fi
-
-case $bin in
+CAT=$({
+        if [[ $SKIP ]]; then
+            $SKIP "$image"
+        else
+            cat "$image"
+        fi } | {
+        read -N 6 bin
+        case $bin in
             $'\x1f\x8b'*)
-        CAT="zcat --";;
+                echo "zcat --"
+                ;;
             BZh*)
-        CAT="bzcat --";;
+                echo "bzcat --"
+                ;;
             $'\x71\xc7'*|070701)
-        CAT="cat --"
+                echo "cat --"
                 ;;
             $'\x02\x21'*)
-        CAT="lz4 -d -c";;
+                echo "lz4 -d -c"
+                ;;
             *)
-        CAT="xzcat --";
                 if echo "test"|xz|xzcat --single-stream >/dev/null 2>&1; then
-            CAT="xzcat --single-stream --"
+                    echo "xzcat --single-stream --"
+                else
+                    echo "xzcat --"
                 fi
                 ;;
-esac
+        esac
+    })
 
 skipcpio()
 {