Fix this warning:

arch/arm/mm/init.c: In function 'mem_init':
arch/arm/mm/init.c:644: warning: format '%08lx' expects type
'long unsigned int', but argument 12 has type 'unsigned int'

And removes the useless parens and white space.
Reported-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>