Remove unused `zpool_is_bootable`

Otherwise compiler errors with:

```
libzfs_pool.c:449:1: error: 'zpool_is_bootable'
 defined but not used [-Werror=unused-function]
```

Reviewed-by: Ryan Moeller <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: George Melikov <[email protected]>
Closes #10734 

1 files changed, 0 insertions, 11 deletions

diff --git a/lib/libzfs/libzfs_pool.c b/lib/libzfs/libzfs_pool.c
index b75ab3ec1..2501965e4 100644
--- a/lib/libzfs/libzfs_pool.c
+++ b/lib/libzfs/libzfs_pool.c
@@ -445,17 +445,6 @@ bootfs_name_valid(const char *pool, const char *bootfs)
 	return (B_FALSE);
 }
 
-static boolean_t
-zpool_is_bootable(zpool_handle_t *zhp)
-{
-	char bootfs[ZFS_MAX_DATASET_NAME_LEN];
-
-	return (zpool_get_prop(zhp, ZPOOL_PROP_BOOTFS, bootfs,
-	    sizeof (bootfs), NULL, B_FALSE) == 0 && strncmp(bootfs, "-",
-	    sizeof (bootfs)) != 0);
-}
-
-
 /*
  * Given an nvlist of zpool properties to be set, validate that they are
  * correct, and parse any numeric properties (index, boolean, etc) if they are