staging: erofs: avoid opened loop codes

Use __GFP_NOFAIL to avoid opened loop codes in z_erofs_vle_unzip().
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190716094422.110805-1-yuchao0@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/erofs/unzip_vle.c

@@ -921,18 +921,18 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 		 mutex_trylock(&z_pagemap_global_lock))
 		pages = z_pagemap_global;
 	else {
-repeat:
+		gfp_t gfp_flags = GFP_KERNEL;
+
+		if (nr_pages > Z_EROFS_VLE_VMAP_GLOBAL_PAGES)
+			gfp_flags |= __GFP_NOFAIL;
+
 		pages = kvmalloc_array(nr_pages, sizeof(struct page *),
-				       GFP_KERNEL);
+				       gfp_flags);
 
 		/* fallback to global pagemap for the lowmem scenario */
 		if (unlikely(!pages)) {
-			if (nr_pages > Z_EROFS_VLE_VMAP_GLOBAL_PAGES)
-				goto repeat;
-			else {
-				mutex_lock(&z_pagemap_global_lock);
-				pages = z_pagemap_global;
-			}
+			mutex_lock(&z_pagemap_global_lock);
+			pages = z_pagemap_global;
 		}
 	}