Changed visibility of get_block_device_size

Change-Id: I5d27f5f50275017134a48eed8d89e452353777f1
diff --git a/ext4_utils/ext4_utils.c b/ext4_utils/ext4_utils.c
index c3bec96..d4fbc7c 100644
--- a/ext4_utils/ext4_utils.c
+++ b/ext4_utils/ext4_utils.c
@@ -388,7 +388,7 @@
 	}
 }
 
-static u64 get_block_device_size(int fd)
+u64 get_block_device_size(int fd)
 {
 	u64 size = 0;
 	int ret;