fibmap: pull in sys/sysmacros.h for major/minor

fibmap: pull in sys/sysmacros.h for major/minor

These funcs are provided by sys/sysmacros.h, so include the header
directly.  Building with alternative C libraries can fail otherwise
like so:

fibmap.c: In function 'print_stat':
fibmap.c:36:32: warning: implicit declaration of function 'major' [-Wimplicit-function-declaration]
  printf("dev       [%d:%d]\n", major(st->st_dev), minor(st->st_dev));
                                ^
fibmap.c:36:51: warning: implicit declaration of function 'minor' [-Wimplicit-function-declaration]
  printf("dev       [%d:%d]\n", major(st->st_dev), minor(st->st_dev));
                                                   ^
fibmap.o: In function 'print_stat':
tools/fibmap.c:36: undefined reference to 'minor'
tools/fibmap.c:36: undefined reference to 'major'
fibmap.o: In function 'stat_bdev':
tools/fibmap.c:59: undefined reference to 'minor'
tools/fibmap.c:59: undefined reference to 'major'

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>