ANDROID: dm-bow: handle STATUSTYPE_IMA

Fix the following compiler warning caused by STATUSTYPE_IMA being added
upstream:

    drivers/md/dm-bow.c: In function ‘dm_bow_status’:
    drivers/md/dm-bow.c:1239:2: warning: enumeration value ‘STATUSTYPE_IMA’ not handled in switch [-Wswitch]
     1239 |  switch (type) {
          |  ^~~~~~

Until IMA data is defined for this target (currently there is no need to
do so), the right thing to do is to just return an empty string.

This should be folded into ANDROID-dm-bow-Add-dm-bow-feature.patch.

Bug: 129280212
Fixes: bc2f6edebd ("Merge 9e9fb7655e ("Merge tag 'net-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next") into android-mainline")
Change-Id: I8b0e7c9d67f20071cdad8e7cb6940a9e35623e31
Signed-off-by: Eric Biggers <ebiggers@google.com>

drivers/md/dm-bow.c

@@ -1238,6 +1238,7 @@ static void dm_bow_status(struct dm_target *ti, status_type_t type,
 {
 	switch (type) {
 	case STATUSTYPE_INFO:
+	case STATUSTYPE_IMA:
 		if (maxlen)
 			result[0] = 0;
 		break;