fix(load_fstype): avoid false positive searchs

Refactor to avoid substring matches
  and to speed processing.
Also avoid xtracing.

modules.d/99base/dracut-lib.sh

@@ -1140,5 +1140,10 @@ remove_hostonly_files() {
 # returns OK if kernel_module is loaded
 # modprobe fails if /lib/modules is not available (--no-kernel use case)
 load_fstype() {
-    strstr "$(cat /proc/filesystems)" "${2:-$1}" || modprobe "$1"
+    local - fs _fs="${2:-$1}"
+    set +x
+    while read -r d fs || [ "$d" ]; do
+        [ "${fs:-$d}" = "$_fs" ] && return 0
+    done < /proc/filesystems
+    modprobe "$1"
 }