cifs: fix pcchunk length type in smb2_copychunk_range

Change type of pcchunk->Length from u32 to u64 to match
smb2_copychunk_range arguments type. Fixes the problem where performing
server-side copy with CIFS_IOC_COPYCHUNK_FILE ioctl resulted in incomplete
copy of large files while returning -EINVAL.

Fixes: 9bf0c9cd ("CIFS: Fix SMB2/SMB3 Copy offload support (refcopy) for large files")
Cc: <stable@vger.kernel.org>
Signed-off-by: Pawel Witek <pawel.ireneusz.witek@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/smb2ops.c

@@ -1682,7 +1682,7 @@ smb2_copychunk_range(const unsigned int xid,
 		pcchunk->SourceOffset = cpu_to_le64(src_off);
 		pcchunk->TargetOffset = cpu_to_le64(dest_off);
 		pcchunk->Length =
-			cpu_to_le32(min_t(u32, len, tcon->max_bytes_chunk));
+			cpu_to_le32(min_t(u64, len, tcon->max_bytes_chunk));
 
 		/* Request server copy to target from src identified by key */
 		kfree(retbuf);