fbcon: fix monochrome color value calculation

Commit 22af89aa

 ("fbcon: replace mono_col
macro with static inline") changed the order of operations for computing
monochrome color values.  This generates 0xffff000f instead of 0x0000000f
for a 4 bit monochrome color, leading to image corruption if it is passed
to cfb_imageblit or other similar functions.  Fix it up.

Cc: Harvey Harrison <harvey.harrison@gmail.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: <stable@kernel.org>		[2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>