KVM: SVM: no need to call access_ok() in LAUNCH_MEASURE command

KVM: SVM: no need to call access_ok() in LAUNCH_MEASURE command

Using the access_ok() to validate the input before issuing the SEV
command does not buy us anything in this case. If userland is
giving us a garbage pointer then copy_to_user() will catch it when we try
to return the measurement.

Suggested-by: Al Viro <[email protected]>
Fixes: 0d0736f76347 (KVM: SVM: Add support for KVM_SEV_LAUNCH_MEASURE ...)
Cc: Paolo Bonzini <[email protected]>
Cc: Radim Krčmář <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Tom Lendacky <[email protected]>
Cc: [email protected]
Cc: Joerg Roedel <[email protected]>
Signed-off-by: Brijesh Singh <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>