sparc: Correct ctx->saw_frame_pointer logic.

sparc: Correct ctx->saw_frame_pointer logic.

[ Upstream commit e2ac579a7a18bcd9e8cf14cf42eac0b8a2ba6c4b ]

We need to initialize the frame pointer register not just if it is
seen as a source operand, but also if it is seen as the destination
operand of a store or an atomic instruction (which effectively is a
source operand).

This is exercised by test_verifier's "non-invalid fp arithmetic"

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>