i386: Remove osxsave CPUID flag name

OSXAVE is not a static feature flag: it changes dynamically at
runtime depending on CR4, and it was never configurable: KVM
never returned OSXSAVE on GET_SUPPORTED_CPUID, and it is not
included in TCG_EXT_FEATURES.

Remove OSXSAVE from the feature name array so users don't try to
configure it manually.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Message-Id: <20180611203855.13269-1-ehabkost@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

target/i386/cpu.c

@@ -788,7 +788,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
             "fma", "cx16", "xtpr", "pdcm",
             NULL, "pcid", "dca", "sse4.1",
             "sse4.2", "x2apic", "movbe", "popcnt",
-            "tsc-deadline", "aes", "xsave", "osxsave",
+            "tsc-deadline", "aes", "xsave", NULL /* osxsave */,
             "avx", "f16c", "rdrand", "hypervisor",
         },
         .cpuid_eax = 1, .cpuid_reg = R_ECX,