Fixed edge case in kernel argument injection

Debian 9 installer doesn't have kernel arguments so the iommu fix
wasn't being applied properly.

initrd/bin/kexec-boot

@@ -45,6 +45,7 @@ fix_file_path() {
 	fi
 }
 
+adjusted_cmd_line="n"
 adjust_cmd_line() {
 	if [ -n "$cmdremove" ]; then
 		for i in $cmdremove; do
@@ -55,6 +56,7 @@ adjust_cmd_line() {
 	if [ -n "$cmdadd" ]; then
 		cmdline="$cmdline $cmdadd"
 	fi
+	adjusted_cmd_line="y"
 }
 
 module_number="1"
@@ -116,6 +118,14 @@ done << EOF
 $kexecparams
 EOF
 
+if [ "$adjusted_cmd_line" = "n" ]; then
+	if [ "$kexectype" = "elf" ]; then
+		kexeccmd="$kexeccmd --append=\"$cmdadd\""
+	else
+		die "Failed to add required kernel commands: $cmdadd"
+	fi
+fi
+
 if [ "$dryrun" = "y" ]; then exit 0; fi
 
 echo "Loading the new kernel:"

initrd/bin/kexec-parse-boot

@@ -2,7 +2,10 @@
 set -e -o pipefail
 bootdir="$1"
 file="$2"
-filedir=`dirname $file`
+
+if [ -z "$bootdir" -o -z "$file" ]; then
+	die "Usage: $0 /boot/ /boot/grub/grub.cfg"
+fi
 
 reset_entry() {
 	name=""
@@ -13,6 +16,7 @@ reset_entry() {
 	append=""
 }
 
+filedir=`dirname $file`
 bootdir=${bootdir%%"/"}
 bootlen=${#bootdir}
 appenddir=${filedir:$bootlen}
@@ -111,7 +115,7 @@ syslinux_end() {
 				*) newappend="$newappend $param" ;;
 			esac
 		done
-		append="$newappend"
+		append="${newappend##' '}"
 	fi
 
 	echo_entry
@@ -196,7 +200,7 @@ do
 			syslinux_entry
 			;;
 	esac
-done < $file
+done < "$file"
 
 # handle EOF case
 if [ "$state" = "syslinux" ]; then