btrfs-progs: remove device_get_partition_size_fd()

The last user of the helper is removed in commit 585ac14
("btrfs-progs: use btrfs_device_size() instead of
device_get_partition_size_fd()"), and that helper is not generic enough
to handle regular files.

So let's just remove it.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>

Author: adam900710

common/device-utils.c

@@ -323,19 +323,6 @@ u64 device_get_partition_size_fd_stat(int fd, const struct stat *st)
 	return 0;
 }
 
-/*
- * Read partition size using the low-level ioctl
- */
-u64 device_get_partition_size_fd(int fd)
-{
-	u64 result;
-
-	if (ioctl(fd, BLKGETSIZE64, &result) < 0)
-		return 0;
-
-	return result;
-}
-
 static u64 device_get_partition_size_sysfs(const char *dev)
 {
 	int ret;

common/device-utils.h

@@ -43,7 +43,6 @@ enum {
 int device_discard_blocks(int fd, u64 start, u64 len);
 int device_zero_blocks(int fd, off_t start, size_t len, const bool direct);
 u64 device_get_partition_size(const char *dev);
-u64 device_get_partition_size_fd(int fd);
 u64 device_get_partition_size_fd_stat(int fd, const struct stat *st);
 int device_get_queue_param(const char *file, const char *param, char *buf, size_t len);
 u64 device_get_zone_unusable(int fd, u64 flags);