[PATCH v2] tpm_crb: Remove dead code from crb_map_res()

[Jarkko Sakkinen <jarkko@kernel.org>]

In all the pre-existing call sites both @iomem and @iobase_ptr are either
both NULL or have a valid address.

Add an invariant for the expeced conditions and remove a dead basic block.
The second block is dead given that if @iomem turns out not to be NULL,
neither can't be @iobase_ptr.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
v2:
- Updated the commit message in order to clarify things better.
- Updated the invariant in order to address checkpatch.pl --strict
  errors.
 drivers/char/tpm/tpm_crb.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index ceb4100ba400..833226966fa2 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -570,15 +570,12 @@ static void __iomem *crb_map_res(struct device *dev, struct resource *iores,
 	if (start != new_res.start)
 		return IOMEM_ERR_PTR(-EINVAL);

+	if (!iores != !iobase_ptr)
+		return IOMEM_ERR_PTR(-EINVAL);
+
 	if (!iores)
 		return devm_ioremap_resource(dev, &new_res);

-	if (!*iobase_ptr) {
-		*iobase_ptr = devm_ioremap_resource(dev, iores);
-		if (IS_ERR(*iobase_ptr))
-			return *iobase_ptr;
-	}
-
 	return *iobase_ptr + (new_res.start - iores->start);
 }

--
2.47.3