Use jinja for loop

Signed-off-by: Alan Moore <alan.moore@canonical.com>

Author: alanmcanonical

shared/macros/10-bash.jinja

@@ -1965,25 +1965,25 @@ fi
 #}}
 {{%- macro update_etc_default_grub_manually(arg_name, arg_name_value) -%}}
 {{%- if 'ubuntu' in product -%}}
-{{%- set grub_vars = "GRUB_CMDLINE_LINUX GRUB_CMDLINE_LINUX_DEFAULT" -%}}
+{{%- set grub_vars = ['GRUB_CMDLINE_LINUX', 'GRUB_CMDLINE_LINUX_DEFAULT'] -%}}
 {{%- else -%}}
-{{%- set grub_vars = "GRUB_CMDLINE_LINUX" -%}}
+{{%- set grub_vars = ['GRUB_CMDLINE_LINUX'] -%}}
 {{%- endif -%}}
 
 # Correct the form of default kernel command line in GRUB
-for grub_var in {{{ grub_vars }}}; do
-    if grep -q "^\s*${grub_var}=\".*{{{ arg_name }}}=.*\"" '/etc/default/grub' ; then
-        # modify the GRUB command-line if an {{{ arg_name }}}= arg already exists
-        sed -i "s/\(^\s*${grub_var}=\".*\){{{ arg_name }}}=[^[:space:]]\+\(.*\"\)/\1{{{ arg_name_value }}}\2/" '/etc/default/grub'
-    # Add to already existing parameters
-    elif grep -q "^\s*${grub_var}=" '/etc/default/grub' ; then
-        # no {{{ arg_name }}}=arg is present, append it
-        sed -i "s/\(^\s*${grub_var}=\".*\)\"/\1 {{{ arg_name_value }}}\"/" '/etc/default/grub'
-    # Add parameters line if completely missing
-    else
-        echo "${grub_var}=\"{{{ arg_name_value }}}\"" >> '/etc/default/grub'
-    fi
-done
+{{%- for grub_var in grub_vars %}}
+if grep -q '^\s*{{{ grub_var }}}=.*{{{ arg_name }}}=.*\"' '/etc/default/grub' ; then
+    # modify the GRUB command-line if an {{{ arg_name }}}= arg already exists
+    sed -i 's/\(^\s*{{{ grub_var }}}=".*\){{{ arg_name }}}=[^[:space:]]\+\(.*"\)/\1{{{ arg_name_value }}}\2/' '/etc/default/grub'
+# Add to already existing parameters
+elif grep -q '^\s*{{{ grub_var }}}=' '/etc/default/grub' ; then
+    # no {{{ arg_name }}}=arg is present, append it
+    sed -i 's/\(^\s*{{{ grub_var }}}=".*\)"/\1 {{{ arg_name_value }}}"/' '/etc/default/grub'
+# Add parameters line if completely missing
+else
+    echo '{{{ grub_var }}}="{{{ arg_name_value }}}"' >> '/etc/default/grub'
+fi
+{{%- endfor %}}
 {{%- endmacro %}}