remove quotes from --label creation for bcachefs

fixes device groups, for example where the disko config given looks like:

label = "fast.dev1";

after formatting, the device has a literal label of "fast.dev1" which
breaks bcachefs device groups:

echo fast > /sys/fs/bcachefs/<id>/options/foreground_target

gives the error Invalid argument, echo fast.dev1 fails as well

echo "\"fast\"" fails the same, however echo "\"fast.dev1\"" succeeds

after this, device labels and groups work as expected and any component
of the label can be used for a *_target

Author: Mitch Fossen

lib/types/bcachefs.nix

@@ -66,7 +66,7 @@
       default = ''
         # Write device arguments to temporary directory for bcachefs_filesystem.
         {
-          printf '%s\n' '--label="${config.label}"';
+          printf '%s\n' '--label=${config.label}';
           ${lib.concatMapStrings (args: ''printf '%s\n' '${args}';'') config.extraFormatArgs}
           printf '%s\n' '${config.device}';
         } >> "$disko_devices_dir/bcachefs-${lib.escapeShellArg config.filesystem}";

tests/bcachefs.nix

@@ -48,10 +48,10 @@ diskoLib.testLib.makeDiskoTest {
     # Verify device membership and labels.
     machine.succeed("bcachefs show-super /dev/vda2 | grep 'Devices:' | grep -q '3'");
     machine.succeed("bcachefs show-super /dev/vdd1 | grep 'Devices:' | grep -q '1'");
-    machine.succeed("bcachefs show-super /dev/vda2 | grep 'Label:' | grep -q 'vdb2'");
-    machine.succeed("bcachefs show-super /dev/vda2 | grep 'Label:' | grep -q 'vdc1'");
-    machine.succeed("bcachefs show-super /dev/vda2 | grep 'Label:' | grep -q 'vdd1'");
-    machine.succeed("bcachefs show-super /dev/vdd1 | grep 'Label:' | grep -q 'vde1'");
+    machine.succeed("bcachefs show-super /dev/vda2 | grep -qE '^[[:space:]]+Label:[[:space:]]+vdb2[[:space:]]\([[:digit:]]+\)'");
+    machine.succeed("bcachefs show-super /dev/vda2 | grep -qE '^[[:space:]]+Label:[[:space:]]+vdc1[[:space:]]\([[:digit:]]+\)'");
+    machine.succeed("bcachefs show-super /dev/vda2 | grep -qE '^[[:space:]]+Label:[[:space:]]+vdd1[[:space:]]\([[:digit:]]+\)'");
+    machine.succeed("bcachefs show-super /dev/vdd1 | grep -qE '^[[:space:]]+Label:[[:space:]]+vde1[[:space:]]\([[:digit:]]+\)'");
     machine.fail("bcachefs show-super /dev/vda2 | grep 'Label:' | grep -q 'non-existent'");
 
     # @todo Verify format arguments.