unsigned var->pixclock cannot be less than 0
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>