Drivers: hv: vmbus: Clean up sscanf format specifier in target_cpu_store()

Drivers: hv: vmbus: Clean up sscanf format specifier in target_cpu_store()

The target_cpu_store() function parses the target CPU from the sysfs
buffer using sscanf(). The format string currently uses "%uu", which
is redundant. The compiler ignores the extra "u", so there is no
incorrect parsing at runtime.

Update the format string to use "%u" for clarity and consistency.

Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>