selftests: KVM: Don't clobber XMM register when read

There is no need to clobber a register that is only being read from.
Oops. Drop the XMM register from the clobbers list.

Signed-off-by: Oliver Upton <oupton@google.com>
Message-Id: <20210927223621.50178-1-oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/include/x86_64/processor.h

@@ -315,7 +315,7 @@ static inline void set_xmm(int n, unsigned long val)
 #define GET_XMM(__xmm)							\
 ({									\
 	unsigned long __val;						\
-	asm volatile("movq %%"#__xmm", %0" : "=r"(__val) : : #__xmm);	\
+	asm volatile("movq %%"#__xmm", %0" : "=r"(__val));		\
 	__val;								\
 })