include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures

For architectures using __WARN_TAINT, the WARN_ON macro did not print
out the "cut here" string.  The other WARN_XXX macros would print "cut
here" inside __warn_printk, which is not called for WARN_ON since it
doesn't have a message to print.

Link: http://lkml.kernel.org/r/20190624154831.163888-1-ddavenport@chromium.org
Fixes: a7bed27a ("bug: fix "cut here" location for __WARN_TAINT architectures")
Signed-off-by: NDrew Davenport <ddavenport@chromium.org>
Acked-by: NKees Cook <keescook@chromium.org>
Tested-by: NKees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/asm-generic/bug.h

@@ -104,8 +104,10 @@ extern void warn_slowpath_null(const char *file, const int line);
 	warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
 #else
 extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
-#define __WARN()		__WARN_TAINT(TAINT_WARN)
-#define __WARN_printf(arg...)	do { __warn_printk(arg); __WARN(); } while (0)
+#define __WARN() do { \
+	printk(KERN_WARNING CUT_HERE); __WARN_TAINT(TAINT_WARN); \
+} while (0)
+#define __WARN_printf(arg...)	__WARN_printf_taint(TAINT_WARN, arg)
 #define __WARN_printf_taint(taint, arg...)				\
 	do { __warn_printk(arg); __WARN_TAINT(taint); } while (0)
 #endif