memory returned as part of nvmem_read via qfprom_read should be
freed by the consumer once done.
Existing code is not doing it so fix it.

Below memory leak detected by kmemleak
   [<ffffff80088b7658>] kmemleak_alloc+0x50/0x84
    [<ffffff80081df120>] __kmalloc+0xe8/0x168
    [<ffffff80086db350>] nvmem_cell_read+0x30/0x80
    [<ffffff8008632790>] qfprom_read+0x4c/0x7c
    [<ffffff80086335a4>] calibrate_v1+0x34/0x204
    [<ffffff8008632518>] tsens_probe+0x164/0x258
    [<ffffff80084e0a1c>] platform_drv_probe+0x80/0xa0
    [<ffffff80084de4f4>] really_probe+0x208/0x248
    [<ffffff80084de2c4>] driver_probe_device+0x98/0xc0
    [<ffffff80084dec54>] __device_attach_driver+0x9c/0xac
    [<ffffff80084dca74>] bus_for_each_drv+0x60/0x8c
    [<ffffff80084de634>] __device_attach+0x8c/0x100
    [<ffffff80084de6c8>] device_initial_probe+0x20/0x28
    [<ffffff80084dcbb8>] bus_probe_device+0x34/0x7c
    [<ffffff80084deb08>] deferred_probe_work_func+0x6c/0x98
    [<ffffff80080c3da8>] process_one_work+0x160/0x2f8

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>