msm: camera: sensor: Validate eeprom_name string length

Validate eeprom_name string length before copying into
the userspace buffer.
If more data than required is copied, userspace has the access to
some of kernel data which is not intended.

CRs-Fixed: 1090007
Change-Id: Id40a287e0b1a93cc15d9b02c757fe9f347e285f2
Signed-off-by: Rajesh Bondugula <rajeshb@codeaurora.org>
Signed-off-by: VijayaKumar T M <vtmuni@codeaurora.org>
Signed-off-by: Yang Guang <guyang@codeaurora.org>