Revert "x86/bugs: Use fixed addressing for VERW operand"

This was reverts commit 8009479e.

It was originally in x86/urgent, but was deemed wrong so got zapped.
But in the meantime, x86/urgent had been merged into x86/apic to
resolve a conflict.  I didn't notice the merge so didn't zap it
from x86/apic and it managed to make it up with the x86/apic
material.

The reverted commit is known to cause some KASAN problems.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>

arch/x86/include/asm/nospec-branch.h

@@ -323,7 +323,7 @@
  * Note: Only the memory operand variant of VERW clears the CPU buffers.
  */
 .macro CLEAR_CPU_BUFFERS
-	ALTERNATIVE "", __stringify(verw mds_verw_sel), X86_FEATURE_CLEAR_CPU_BUF
+	ALTERNATIVE "", __stringify(verw _ASM_RIP(mds_verw_sel)), X86_FEATURE_CLEAR_CPU_BUF
 .endm
 
 #else /* __ASSEMBLY__ */