remove previous block_count detection from lfs_format

lfs.c

@@ -4416,20 +4416,7 @@ static int lfs_rawformat(lfs_t *lfs, const struct lfs_config *cfg) {
             return err;
         }
 
-        if (cfg->block_count == 0) {
-            // Attempt to read a (possibly) prior superblock
-            lfs_superblock_t superblock;
-            err = lfs_scan_for_superblock(lfs, &superblock);
-            if (err) {
-                goto cleanup;
-            }
-            lfs->block_count = superblock.block_count;
-
-            err = lfs_validate_superblock(lfs, &superblock);
-            if (err) {
-                goto cleanup;
-            }
-        }
+        LFS_ASSERT(cfg->block_count != 0);
 
         // create free lookahead
         memset(lfs->free.buffer, 0, lfs->cfg->lookahead_size);

tests/test_superblocks.toml

@@ -5,29 +5,6 @@ code = '''
     lfs_format(&lfs, cfg) => 0;
 '''
 
-# formatting from interpretting a previous superblock block_count
-[cases.test_superblocks_format_unknown_block_count]
-code = '''
-    lfs_t lfs;
-    lfs_format(&lfs, cfg) => 0;
-    assert(lfs.block_count == cfg->block_count);
-
-    memset(&lfs, 0, sizeof(lfs));
-    struct lfs_config tweaked_cfg = *cfg;
-    tweaked_cfg.block_count = 0;
-    lfs_format(&lfs, &tweaked_cfg) => 0;
-    assert(lfs.block_count == cfg->block_count);
-'''
-
-# formatting from interpretting a non-existent previous superblock block_count
-[cases.test_superblocks_format_unknown_block_count_failure]
-code = '''
-    lfs_t lfs;
-    struct lfs_config tweaked_cfg = *cfg;
-    tweaked_cfg.block_count = 0;
-    lfs_format(&lfs, &tweaked_cfg) => LFS_ERR_CORRUPT;
-'''
-
 # mount/unmount
 [cases.test_superblocks_mount]
 code = '''