regmap: regcache-rbtree: Fix present bitmap resize

regmap: regcache-rbtree: Fix present bitmap resize

commit 328f494d95aac8bd4896aea2328bc281053bcb71 upstream.

When inserting a new register into a block at the lower end the present
bitmap is currently shifted into the wrong direction. The effect of this is
that the bitmap becomes corrupted and registers which are present might be
reported as not present and vice versa.

Fix this by shifting left rather than right.

Fixes: 472fdec7380c("regmap: rbtree: Reduce number of nodes, take 2")
Reported-by: Daniel Baluta <daniel.baluta@gmail.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>