MIPS: bpf: Drop update_on_xread and always initialize the X register
MIPS: bpf: Drop update_on_xread and always initialize the X register

Previously, update_on_xread() only set the reset flag if SEEN_X hasn't
been set already. However, SEEN_X is used to indicate that X is used
as destination or source register so there are some cases where X
is only used as source register and we really need to make sure that it
has been initialized in time. As a result of which, drop this function and
always set X to zero if it's used in any of the opcodes.

Signed-off-by: Markos Chandras <5cdbcb0e11d2b5ebc39222958c54a1c6329d0c9d@imgtec.com>
Cc: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>
Cc: Daniel Borkmann <9ff04a02a69f376b2b9aeec27187017cbf3cf5f9@redhat.com>
Cc: Alexei Starovoitov <c24c0248770ae98831f8a654310d4c2e07514c61@plumgrid.com>
Cc: 1099b3bee480025a15c1b622ecdea77a1d6d7166@vger.kernel.org
Cc: 562397917b9a8bf316569a848858b12fb417723f@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7133/
Signed-off-by: Ralf Baechle <92f48d309cda194c8eda36aa8f9ae28c488fa208@linux-mips.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs