jfs: Fix fortify moan in symlink

JFS has in jfs_incore.h:

/* _inline may overflow into _inline_ea when needed */
/* _inline_ea may overlay the last part of
* file._xtroot if maxentry = XTROOTINITSLOT
*/
union {
struct {
/* 128: inline symlink */
unchar _inline[128];
/* 128: inline extended attr */
unchar _inline_ea[128];
};
unchar _inline_all[256];

and currently the symlink code copies into _inline;
if this is larger than 128 bytes it triggers a fortify warning of the
form:

memcpy: detected field-spanning write (size 132) of single field
"ip->i_link" at fs/jfs/namei.c:950 (size 18446744073709551615)

when it's actually OK.

Copy it into _inline_all instead.

Reported-by: [e-mail]
Signed-off-by: Dr. David Alan Gilbert <[e-mail]>
Reviewed-by: Kees Cook <[e-mail]>
Signed-off-by: Dave Kleikamp <[e-mail]>

fs/jfs/namei.c

···
 	if (ssize <= IDATASIZE) {
 		ip->i_op = &jfs_fast_symlink_inode_operations;
 
-		ip->i_link = JFS_IP(ip)->i_inline;
+		ip->i_link = JFS_IP(ip)->i_inline_all;
 		memcpy(ip->i_link, name, ssize);
 		ip->i_size = ssize - 1;