ext4: change the type of blocksize in ext4_mb_init_cache()

The return value type of i_blocksize() is 'unsigned int', so the
type of blocksize has been modified from 'int' to 'unsigned int'
to ensure data type consistency.
Signed-off-by: Lu Hongfei <luhongfei@vivo.com>
Link: https://lore.kernel.org/r/20230707105516.9156-1-luhongfei@vivo.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/mballoc.c

@@ -1256,7 +1256,7 @@ void ext4_mb_generate_buddy(struct super_block *sb,
 static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
 {
 	ext4_group_t ngroups;
-	int blocksize;
+	unsigned int blocksize;
 	int blocks_per_page;
 	int groups_per_page;
 	int err = 0;