f2fs: make "f2fs_fault_name[]" const char *

Those strings are immutable.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -67,7 +67,7 @@ struct f2fs_fault_info {
 	unsigned int inject_type;
 };
 
-extern char *f2fs_fault_name[FAULT_MAX];
+extern const char *f2fs_fault_name[FAULT_MAX];
 #define IS_FAULT_SET(fi, type) ((fi)->inject_type & (1 << (type)))
 #endif
 

fs/f2fs/super.c

@@ -38,7 +38,7 @@ static struct kmem_cache *f2fs_inode_cachep;
 
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 
-char *f2fs_fault_name[FAULT_MAX] = {
+const char *f2fs_fault_name[FAULT_MAX] = {
 	[FAULT_KMALLOC]		= "kmalloc",
 	[FAULT_KVMALLOC]	= "kvmalloc",
 	[FAULT_PAGE_ALLOC]	= "page alloc",