Use correct sscanf() format string for uint64_t

[dim]

Summary

After rS310171, the kernel version of sscanf() now has format string
checking enabled. This now results in a -Werror warning in mlx4ib:

/usr/src/sys/modules/mlx4ib/../../dev/mlx4/mlx4_ib/mlx4_ib_sysfs.c:90:22: error: format specifies type 'unsigned long long *' but the argument has type 'u64 *' (aka 'unsigned long *') [-Werror,-Wformat]
        sscanf(buf, "%llx", &sysadmin_ag_val);
                 ~~~~   ^~~~~~~~~~~~~~~~

Since u64 is a uint64_t, let's use the SCNx64 macro from inttypes.h
instead.

[• hselasky]

Is machine/_inttypes.h the correct header file to include?

I think it is also fine to change the sysadmin_ag_val to unsigned long long, which is currently 64-bit for i386 and amd64 which the mlx4 driver is compiled on.

Don't forget to MFC.

--HPS

[dim]

In D8831#182872, @hselasky wrote:

Is machine/_inttypes.h the correct header file to include?

This is what other drivers appear to include, if they want to get at PRI/SCN macros. Though this isn't a Linux thing.

I think it is also fine to change the sysadmin_ag_val to unsigned long long, which is currently 64-bit for i386 and amd64 which the mlx4 driver is compiled on.

Yes, if that is also acceptable, we don't need the additional include.

[dim]

Just change sysadmin_ag_val to unsigned long long instead.