Almost every use of dev_err in this driver prints the function name.  Abstract
out wrappers to help with this and reduce code duplication.
Acked-by: NPer Forlin <per.forlin@stericsson.com>
Acked-by: NJonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: NRabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>