linux-user: fix flock/flock64 padding

include/uapi/asm-generic/fcntl.h insert a padding macro at
the end of the structures flock and flock64.

This macro is defined to "short __unused;" on sparc,
and "long pad[4]" on mips.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Message-Id: <20180509231123.20864-3-laurent@vivier.eu>

linux-user/syscall_defs.h

@@ -2643,6 +2643,17 @@ struct target_statfs64 {
 #define TARGET_O_SYNC    (TARGET___O_SYNC | TARGET_O_DSYNC)
 #endif
 
+#if defined(TARGET_SPARC)
+#define TARGET_ARCH_FLOCK_PAD abi_short __unused;
+#define TARGET_ARCH_FLOCK64_PAD abi_short __unused;
+#elif defined(TARGET_MIPS)
+#define TARGET_ARCH_FLOCK_PAD abi_long pad[4];
+#define TARGET_ARCH_FLOCK64_PAD
+#else
+#define TARGET_ARCH_FLOCK_PAD
+#define TARGET_ARCH_FLOCK64_PAD
+#endif
+
 struct target_flock {
     short l_type;
     short l_whence;
@@ -2652,9 +2663,7 @@ struct target_flock {
     abi_long l_sysid;
 #endif
     int l_pid;
-#if defined(TARGET_MIPS)
-    abi_long pad[4];
-#endif
+    TARGET_ARCH_FLOCK_PAD
 };
 
 struct target_flock64 {
@@ -2663,6 +2672,7 @@ struct target_flock64 {
     abi_llong l_start;
     abi_llong l_len;
     abi_int   l_pid;
+    TARGET_ARCH_FLOCK64_PAD
 };
 
 struct target_f_owner_ex {