The pseudo_palette has room only for 16 entries, but tdfxfb_setcolreg may
attempt to write more.

Coverity Bug 557
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>