Fix sparse warnings
Fix sparse warnings

Fix the following sparse warnings:

  libcxl.c:665:45: warning: non-ANSI function declaration of function
    'cxl_work_alloc'
  libcxl.c:1029:32: warning: non-ANSI function declaration of function
    'cxl_mmio_try'
  libcxl.c:1043:37: warning: non-ANSI function declaration of function
    'cxl_mmio_success'
  libcxl.c:1169:18: warning: constant 0xffffffffffffffff is so big it is
    unsigned long
  libcxl.c:1190:17: warning: constant 0xffffffffffffffff is so big it is
    unsigned long
  libcxl.c:1300:37: warning: non-ANSI function declaration of function
    'cxl_mmio_install_sigbus_handler'
  libcxl.c:223:9: warning: returning void-valued expression
  libcxl.c:1296:17: warning: returning void-valued expression

Signed-off-by: Andrew Donnellan <efc2d7c347a094a6ec1d918179e819039044c564@au1.ibm.com>

ibm-capi/libcxl,ibm-capi/libcxl