We were getting build warning about unused variable 'ret'.
The commit c749db571dcf has removed the use of ret but missed removing
the variable which is unused now.

Fixes: c749db571dcf ("mfd: lm3533: Simplify function return logic")
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>