i2c: pmcmsp: fix error return from master_xfer

[ Upstream commit 12d9bbc5 ]

Returning -1 (-EPERM) is not appropriate here, go with -EIO.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 1b144df1 ("i2c: New PMC MSP71xx TWI bus driver")
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>