linux-user: x86_64: Don't use 16-bit UIDs

The 64-bit x86 syscall ABI uses 32-bit UIDs; only define
USE_UID16 for 32-bit x86.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index 9e2b3c2..34af15a 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -55,7 +55,8 @@
 #define TARGET_IOC_NRBITS	8
 #define TARGET_IOC_TYPEBITS	8
 
-#if defined(TARGET_I386) || (defined(TARGET_ARM) && defined(TARGET_ABI32)) \
+#if (defined(TARGET_I386) && defined(TARGET_ABI32)) \
+    || (defined(TARGET_ARM) && defined(TARGET_ABI32)) \
     || defined(TARGET_SPARC) \
     || defined(TARGET_M68K) || defined(TARGET_SH4) || defined(TARGET_CRIS)
     /* 16 bit uid wrappers emulation */