x86/bugs: Change L1TF mitigation string to match upstream

Commit 72c6d2d "x86/litf: Introduce vmx status variable" upstream
changed "Page Table Inversion" to "PTE Inversion".  That was part of
the implementation of additional mitigations for VMX which haven't
been applied to this branch.  Just change this string to be consistent
and match documentation.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

arch/x86/kernel/cpu/bugs.c

@@ -1225,7 +1225,7 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
 
 	case X86_BUG_L1TF:
 		if (boot_cpu_has(X86_FEATURE_L1TF_PTEINV))
-			return sprintf(buf, "Mitigation: Page Table Inversion\n");
+			return sprintf(buf, "Mitigation: PTE Inversion\n");
 		break;
 
 	case X86_BUG_MDS: