x86/syscalls: Use the compat versions of rt_sigsuspend() and rt_sigprocmask()

I'm working on some code that detects at build time if there's a
COMPAT_SYSCALL_DEFINE() that is not referenced in the x86 syscall tables.
It catches three offenders: rt_sigsuspend(), rt_sigprocmask(), and
sendfile64().

For rt_sigsuspend() and rt_sigprocmask(), the only potential difference
between the native and compat versions is that the compat version converts
the sigset_t, but, on little endian architectures, the conversion is a
no-op.  This is why they both currently work on x86.

To make the code more consistent, and to make the upcoming patches work,
rewire x86 to use the compat vesions.

sendfile64() is more complicated, and will be addressed separately.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/51643ac3157b5921eae0e172a8a0b1d953e68ebb.1562185330.git.luto@kernel.org

arch/x86/entry/syscalls/syscall_32.tbl

@@ -186,11 +186,11 @@
 172	i386	prctl			sys_prctl			__ia32_sys_prctl
 173	i386	rt_sigreturn		sys_rt_sigreturn		sys32_rt_sigreturn
 174	i386	rt_sigaction		sys_rt_sigaction		__ia32_compat_sys_rt_sigaction
-175	i386	rt_sigprocmask		sys_rt_sigprocmask		__ia32_sys_rt_sigprocmask
+175	i386	rt_sigprocmask		sys_rt_sigprocmask		__ia32_compat_sys_rt_sigprocmask
 176	i386	rt_sigpending		sys_rt_sigpending		__ia32_compat_sys_rt_sigpending
 177	i386	rt_sigtimedwait		sys_rt_sigtimedwait_time32	__ia32_compat_sys_rt_sigtimedwait_time32
 178	i386	rt_sigqueueinfo		sys_rt_sigqueueinfo		__ia32_compat_sys_rt_sigqueueinfo
-179	i386	rt_sigsuspend		sys_rt_sigsuspend		__ia32_sys_rt_sigsuspend
+179	i386	rt_sigsuspend		sys_rt_sigsuspend		__ia32_compat_sys_rt_sigsuspend
 180	i386	pread64			sys_pread64			__ia32_compat_sys_x86_pread
 181	i386	pwrite64		sys_pwrite64			__ia32_compat_sys_x86_pwrite
 182	i386	chown			sys_chown16			__ia32_sys_chown16