vlan: use correct format characters

When compiling with -Wformat, clang emits the following warning:

net/8021q/vlanproc.c:284:22: warning: format specifies type 'unsigned
short' but the argument has type 'int' [-Wformat]
                                   mp->priority, ((mp->vlan_qos >> 13) & 0x7));
                                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

The types of these arguments are unconditionally defined, so this patch
updates the format character to the correct ones for ints and unsigned
ints.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Signed-off-by: Bill Wendling <morbo@google.com>
Link: https://lore.kernel.org/r/20220316213125.2353370-1-morbo@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>