dracut-functions.sh:require_binaries() clarify message

The info message written by require_binaries() was a bit frighten to
users. So just be a little bit more verbose.

If you have ideas on how to improve the message for these "soft"
dependency modules, please submit patches.

dracut-functions.sh

@@ -53,7 +53,7 @@ require_binaries() {
 
     for cmd in "$@"; do
         if ! find_binary "$cmd" &>/dev/null; then
-            dinfo "$_module_name: Could not find command '$cmd'!"
+            dinfo "dracut module '${_module_name#[0-9][0-9]}' will not be installed, because command '$cmd' could not be found!"
             ((_ret++))
         fi
     done