ufs: fix braino in ufs_get_inode_gid() for solaris UFS flavour

BugLink: https://bugs.launchpad.net/bugs/1832661

[ Upstream commit 4e903604 ]

To choose whether to pick the GID from the old (16bit) or new (32bit)
field, we should check if the old gid field is set to 0xffff.  Mainline
checks the old *UID* field instead - cut'n'paste from the corresponding
code in ufs_get_inode_uid().

Fixes: 252e211eSigned-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

fs/ufs/util.h

@@ -228,7 +228,7 @@ ufs_get_inode_gid(struct super_block *sb, struct ufs_inode *inode)
 	case UFS_UID_44BSD:
 		return fs32_to_cpu(sb, inode->ui_u3.ui_44.ui_gid);
 	case UFS_UID_EFT:
-		if (inode->ui_u1.oldids.ui_suid == 0xFFFF)
+		if (inode->ui_u1.oldids.ui_sgid == 0xFFFF)
 			return fs32_to_cpu(sb, inode->ui_u3.ui_sun.ui_gid);
 		/* Fall through */
 	default: