ext4: mballoc: simplify error handling in ext4_init_mballoc()

This patch simplifies error handling logic in ext4_init_mballoc(),
by adding all the cleanups at one place at the end of that function.

There should be no functionality change in this patch.
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/8621a7bc68f7107a9ac4292afeb784515333bd25.1589086800.git.riteshh@linux.ibm.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/mballoc.c

@@ -2913,23 +2913,26 @@ int __init ext4_init_mballoc(void)
 	ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space,
 					SLAB_RECLAIM_ACCOUNT);
 	if (ext4_pspace_cachep == NULL)
-		return -ENOMEM;
+		goto out;
 
 	ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context,
 				    SLAB_RECLAIM_ACCOUNT);
-	if (ext4_ac_cachep == NULL) {
-		kmem_cache_destroy(ext4_pspace_cachep);
-		return -ENOMEM;
-	}
+	if (ext4_ac_cachep == NULL)
+		goto out_pa_free;
 
 	ext4_free_data_cachep = KMEM_CACHE(ext4_free_data,
 					   SLAB_RECLAIM_ACCOUNT);
-	if (ext4_free_data_cachep == NULL) {
-		kmem_cache_destroy(ext4_pspace_cachep);
-		kmem_cache_destroy(ext4_ac_cachep);
-		return -ENOMEM;
-	}
+	if (ext4_free_data_cachep == NULL)
+		goto out_ac_free;
+
 	return 0;
+
+out_ac_free:
+	kmem_cache_destroy(ext4_ac_cachep);
+out_pa_free:
+	kmem_cache_destroy(ext4_pspace_cachep);
+out:
+	return -ENOMEM;
 }
 
 void ext4_exit_mballoc(void)