[klibc] -x c++ breaks non-c++-capable versions of gcc.  Use -x c instead.

-x c++ was a safety for very old versions of gcc, but I had assumed it
would always be available since we're just running the preprocessor.
That apparently isn't the case, so undo that change and just treat it
like C code.  If someone has a really old gcc, it *should* still work
since syscalls.pl will recognize the comments, but presence of quotes
may make it unpredictable.  In other words, no worse off than we
previously were.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/usr/klibc/syscalls/Kbuild b/usr/klibc/syscalls/Kbuild
index f5468a3..487ebf7 100644
--- a/usr/klibc/syscalls/Kbuild
+++ b/usr/klibc/syscalls/Kbuild
@@ -38,7 +38,7 @@
 # We pass -ansi to keep cpp from define e.g. "i386" as well as "__i386__"
 quiet_cmd_syscall.i = GEN     $@
       cmd_syscall.i = $(KLIBCCC) $(klibccflags) -D__ASSEMBLY__ \
-                                -ansi -x c++ -E -o $@ $<
+                                -ansi -x c -E -o $@ $<
 $(obj)/SYSCALLS.i: $(KLIBCSRC)/SYSCALLS.def FORCE
 	$(call if_changed_dep,syscall.i)