lib/vsprintf: Force type of flags value for gfp_t

Sparse is not happy about restricted type being assigned:
  lib/vsprintf.c:1940:23: warning: incorrect type in assignment (different base types)
  lib/vsprintf.c:1940:23:    expected unsigned long [assigned] flags
  lib/vsprintf.c:1940:23:    got restricted gfp_t [usertype]

Force type of flags value to make sparse happy.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200731180825.30575-3-andriy.shevchenko@linux.intel.comSigned-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>

lib/vsprintf.c

@@ -1937,7 +1937,7 @@ char *flags_string(char *buf, char *end, void *flags_ptr,
 		names = vmaflag_names;
 		break;
 	case 'g':
-		flags = *(gfp_t *)flags_ptr;
+		flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
 		names = gfpflag_names;
 		break;
 	default: