Fix format strings

This fix the following build failure:

  CC    libdis-user/microblaze-dis.o
cc1: warnings being treated as errors
microblaze-dis.c: In function 'print_insn_microblaze':
microblaze-dis.c:829: warning: format '%04x' expects type 'unsigned int',
but argument 4 has type 'long unsigned int'
microblaze-dis.c:962: warning: format '%04x' expects type 'unsigned int',
but argument 4 has type 'long unsigned int'

Reported-at: http://www.monstr.eu/wiki/doku.php?id=log:2010-04-13_12_10_00



Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>