KVM: x86: Fix bit shifting in update_intel_pt_cfg

ctl_bitmask in pt_desc is of type u64. When an integer like 0xf is
being left shifted more than 32 bits, the behavior is undefined.

Fix this by adding suffix ULL to integer 0xf.

Addresses-Coverity-ID: 1476095 ("Bad bit shift operation")
Fixes: 6c0f0bba

 ("KVM: x86: Introduce a function to initialize the PT configuration")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>