svm: Fix MISRA 8.2 violation

Misra 8.2 requires named parameters in prototypes.  Use the name from
the implementaiton.

Fixes: 0d19d3aab0 ("svm/nestedsvm: Introduce nested capabilities bit")
Reported-by: Andrew Cooper <andrew.cooper@cloud.com>
Reported-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Signed-off-by: George Dunlap <george.dunlap@cloud.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/arch/x86/include/asm/hvm/nestedhvm.h

@@ -83,7 +83,7 @@ static inline bool vvmcx_valid(const struct vcpu *v)
 }
 
 
-void start_nested_svm(struct hvm_function_table *);
-void start_nested_vmx(struct hvm_function_table *);
+void start_nested_svm(struct hvm_function_table *hvm_function_table);
+void start_nested_vmx(struct hvm_function_table *hvm_function_table);
 
 #endif /* _HVM_NESTEDHVM_H */