fbdev/broadsheetfb: fix memory leak
fbdev/broadsheetfb: fix memory leak

static code analysis from cppcheck reports:

[drivers/video/fbdev/broadsheetfb.c:673]:
  (error) Memory leak: sector_buffer

sector_buffer is not being kfree'd on each call to
broadsheet_spiflash_rewrite_sector(), so free it.

Signed-off-by: Colin Ian King <d100aa70785e45ee8deab668147d941941915c21@canonical.com>
Signed-off-by: Tomi Valkeinen <e1ca4dbb8be1acaf20734fecd2da10ed1d46a9bb@ti.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs