x86/speculation, objtool: Annotate indirect calls/jumps for objtool on 32bit

BugLink: http://bugs.launchpad.net/bugs/1758856

In 9e0e3c51 ("x86/speculation, objtool: Annotate indirect calls/jumps
for objtool") we added annotations for CALL_NOSPEC/JMP_NOSPEC on x86 64bit.
We did not annotate the 32bit path.  Annotate it similarly.

[apw@canonical.com: backported to xenial.]
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>

arch/x86/include/asm/nospec-branch.h

@@ -159,7 +159,10 @@
  * otherwise we'll run out of registers. We don't care about CET
  * here, anyway.
  */
-# define CALL_NOSPEC ALTERNATIVE("call *%[thunk_target]\n",	\
+# define CALL_NOSPEC 						\
+	ALTERNATIVE(						\
+	ANNOTATE_RETPOLINE_SAFE					\
+	"call *%[thunk_target]\n",				\
 	"       jmp    904f;\n"					\
 	"       .align 16\n"					\
 	"901:	call   903f;\n"					\